JP3786171B2 - Method for arranging reinforcing material for panel structure - Google Patents

Description

【００３４】
表１から明らかなように、アウタパネル２の板厚低減による軽量化の効果は補強材８の板厚増加による重量増加を上回るので、アウタパネル２及び補強材８全体としての重量比でみて、７．４％の軽量化を達成することができる。
更に図４を参照して、上述した実施例の構造的な変更に伴う荷重−変位線図での剛性確保の確認を行う。
【００３５】
図中に実線で示される特性（ｔ_p0＝０．７８，ｔ_s0）は、構造変更を行う前の基準板厚における剛性を示している。これに対し、実施例の構造変更を行った場合、その剛性は一点鎖線で示される特性（ｔ_p＝０．６８，２ｔ_s0）に移行するものの、その初期剛性は構造変更前における初期剛性ｋ₀に比較してほとんど低下しておらず、更に、変形の大きい領域での剛性は充分に確保されていることが確認される。これは、板厚を増加することで補強材８の剛性が相対的に増大し、その分、補強材８の荷重分担が増加するという効果に基づいている。
【００３６】
また、アウタパネル２の板厚を低減しても、その初期剛性にほとんど低下がみられないという結果は、上述した補強材８を配置することによりアウタパネル２の初期剛性に余裕が確保されるという効果の裏付けとしても有用である。
なお、図４には実施例以外の構造変更の例として、アウタパネル２の板厚を基準板厚ｔ_p0に保持して補強材８の板厚のみを半分に低減（ｔ_p0＝０．７８，０．５ｔ_s0）した場合の特性が破線にて示されており、また、補強材８の板厚のみを倍増（ｔ_p0＝０．７８，２ｔ_s0）した場合の特性が二点鎖線にて示されている。これら変更例からも明らかなように、変形量の大きい領域において全体として剛性を確保するためには、例えば板厚の増加等による補強材８の構造的な剛性増大がより有効であると認められる。
【００３７】
従って、本実施例ではアウタパネル２及び補強材８の構造的な諸元、例えばその板厚が以下の２つの条件を同時に満足するべく設定される（諸元設定工程）。
（１）アウタパネル２の板厚低減等の構造的な軽量化により、補強材８を含む総重量が相対的に軽減されること。
（２）補強材８の板厚増加等の構造的な剛性増大により、アウタパネル２及び補強部材８の荷重分担を合計した場合の総荷重分担が相対的に増加すること。
【００３８】
なお、例えばアウタパネル２の板厚を低減して軽量化を行っていても、補強材８の板厚を増加した分、総重量が増加していれば、その構造変更は上記（１）の条件を満足しない。また、補強材８の板厚を増加して剛性を増大していても、アウタパネル２の板厚を低減した分、全体としての剛性が低下していれば、その構造変更は上記（２）の条件を満足しないものとなる。これらの場合は、２つの条件を同時に満足するべく板厚を再変更する必要がある。
【００３９】
なお、本発明の発明者は、上記（１）及び（２）の条件を同時に満足するための評価基準として、アウタパネル２及び補強材８の各板厚を構造パラメータとした条件式を提供している。条件式は以下の手順により導かれる。
予め適宜に選択した基準状態でのアウタパネル２及び補強材８の板厚ｔ_p0，ｔ_s0に対し、構造的な変更を行った場合の変更板厚をそれぞれｔ_p，ｔ_sとする。なお、構造変更前の基準板厚ｔ_p0，ｔ_s0は例えば、トラックの車格や仕様等に応じて、通常必要なドア剛性を確保するための板厚に設定しておけばよい。
【００４０】
アウタパネル２の板厚減少分をΔｔ_p、補強材８の板厚増加分をΔｔ_sとすると、これら増減分（差分）は
Δｔ_p＝ｔ_p0−ｔ_p，Δｔｓ＝ｔ_s−ｔ_s0 ・・・(1),(2)
で表される。
次に、補強材８とアウタパネル２との重量比をｗ：１とすると、総重量の軽量化のための条件は次式(3)で表される。
【００４１】
Δｔ_p/ｔ_p0＞Δｔ_s/ｔ_s0・ｗ ・・・(3)
また、構造変更前の基準状態におけるアウタパネル２と補強材８の荷重分担Ｐ_p0、Ｐ_s0を求め、これら部材の構造を変更した場合に増減するべき増減荷重分担をＰ_p，Ｐ_sとする。このとき、アウタパネル２及び補強材８の構造パラメータをそれぞれの板厚により表すと、これら構造パラメータと増減荷重分担Ｐ_p，Ｐ_sとの関係は次式(4),(5)で表すことができる。
【００４２】
Ｐ_p/Ｐ_p0＝（ｔ_p/ｔ_p0）ⁿ，Ｐ_s/Ｐ_s0＝（ｔ_s/ｔ_s0）^m ・・・(4),(5)
一方、構造を変更した場合の全ての部材で負担可能な総荷重分担をＰとし、また、アウタパネル２及び補強材８の荷重分担率をそれぞれｙ_s，ｙ_p、その他の部材の荷重分担率をｚ（≡１−ｙ_s−ｙ_p）とすると、
Ｐ_p＋Ｐ_s＋Ｐ₁＋Ｐ₂＋・・・＋Ｐ_n＝Ｐ ・・・(6)
Ｐ₁＋Ｐ₂＋・・・＋Ｐ_n＝Ｐ₁₀＋Ｐ₂₀＋・・・＋Ｐ_n0＝ｚＰ₀ ・・・(7)
より、構造を変更した場合に相対的に剛性を増加させるための条件として、Ｐ＞Ｐ₀を満足するための板厚の条件を導けばよい。なお、荷重分担率ｙ_p，ｙ_sはそれぞれ、ｙ_p＝Ｐ_p0/Ｐ₀，ｙ_s＝Ｐ_s0/Ｐ₀で定義される。
【００４３】
ここで、上式(4),(5)及び荷重分担率の定義から、
Ｐ_p＝Ｐ_p0（ｔ_p/ｔ_p0）ⁿ＝ｙ_pＰ₀（ｔ_p/ｔ_p0）ⁿ ・・・(8)
Ｐ_s＝Ｐ_s0（ｔ_s/ｔ_s0）^m＝ｙ_sＰ₀（ｔ_s/ｔ_s0）^m ・・・(9)
よって、上記の条件は次式、
ｙ_pＰ₀（ｔ_p/ｔ_p0）ⁿ＋ｙ_sＰ₀（ｔ_s/ｔ_s0）^m＋ｚＰ₀＞Ｐ₀・・・(10)
で表され、上式(10)を更に整理してＰ₀を消去すると、
ｙ_p（ｔ_p/ｔ_p0）ⁿ＋ｙ_s（ｔ_s/ｔ_s0）^m＋ｚ＞１ ・・・(11)
である。ここで、全荷重をアウタパネル２及び補強材８により分担するものとしてｙ_p＋ｙ_s＝１、更にｙ_s＝ｙとおくと、ｙ_p＝１−ｙ，ｚ＝０より式(11)は、
（１−ｙ）・（ｔ_p/ｔ_p0）ⁿ＋ｙ（ｔ_s/ｔ_s0）^m＞１ ・・・(12)
で表される。従って、総重量軽減と張り剛性確保とを同時に満足するための条件式として、例えば上式(3),(12)が提供される。
【００４４】
また、式(12)の左辺＝１を解くことにより、
ｙ₀＝{１−（ｔ_p/ｔ_p0）ⁿ}/{（ｔ_s/ｔ_s0）^m−（ｔ_p/ｔ_p0）ⁿ} ・・・(13)
として構造変更後の荷重分担率ｙ₀を予め定義しておけば、ｙ＞ｙ₀が張り剛性確保のための条件となる。
以上は実施例についての条件式であるが、例えば上述した縦・横補強材の配置プランのように複数本の補強材８を配設する場合にあっては、更に以下の一般式を用いることができる。
【００４５】
ここでは、トラックのドアパネルに限定されないパネル構造体とその補強材についての条件を一般化するものとする。すなわち、構造変更前の基準状態においてパネル構造体にｎ本（少なくとも１本）の補強材を取り付けた状態で、パネル構造体の荷重点において０から逐次増大する荷重を加える。この荷重に対するパネル構造体及び各補強材の荷重分担を求め、パネル構造体の荷重分担をＰ_p0、各補強材（ｓ１〜ｓｎとする）の荷重分担をＰ_s10，・・・，Ｐ_sn0とする。
【００４６】
ここで、基準状態における荷重分担の合計、つまり、総荷重分担Ｐ₀は、
Ｐ₀＝Ｐ_p0＋Ｐ_s10＋・・・＋Ｐ_sn0 ・・・(14)
である。この場合、加えられた全荷重はパネル構造体及び全ての補強材により分担されるので、総荷重分担Ｐ₀と全荷重とは同一である。
一方、パネル構造体及び各補強材の荷重分担が構造の変更により増減する場合、その変更後の増減荷重分担をＰ_p，Ｐ_s1，・・・，Ｐ_nとすると、構造変更後に負担可能となる全荷重Ｐは、
Ｐ＝Ｐ_p＋Ｐ_s1＋・・・＋Ｐ_sn ・・・(15)
である。
【００４７】
例えば、各部材の板厚を増減することでその構造を変更する場合、その変更後における各部材の増減荷重分担は、その板厚を構造パラメータとして表すことができる。ここで、基準状態における各部材のパネル構造体の板厚をｔ_p0、各補強材の板厚をｔ_s10，・・・，ｔ_sn0、また、その変更後の板厚をｔ_p，ｔ_s1，・・・，ｔ_snとすると、ｉ部材の増減荷重分担Ｐ_iは次式、
Ｐ_i＝Ｐ_i0(ｔ_i/ｔ_i0)^mi＝ｙ_iＰ₀(ｔ_i/ｔ_i0)^mi ・・・(16)
で表される。なお、ｉ＝ｐ，ｓ１，・・・，ｓｎである。
【００４８】
従って、上式(15),(16)から構造変更後に負担可能な全荷重を増加させるための条件式、
ｙ_p(ｔ_p/ｔ_p0)^mp＋ｙ_s1(ｔ_s1/ｔ_s10)^ms1＋・・・＋ｙ_sn(ｔ_sn/ｔ_sn0)^msn≧1・・・(17)
を得ることができる。
更に、ｉ部材の単体重量をＷ_i0として、その単位板厚あたりの重量を、
ｗ_i0＝Ｗ_i0/ｔ_i0 ・・・(18)
とし、また、各部材の板厚の増減分をΔ_tp，Δｔ_s1，・・・，Δｔ_snとすると、総荷重分担増加と同時に満足するべき総重量軽減のための条件は、
ｗ_p0Δｔ_p＋ｗ_s10Δｔ_s1＋・・・＋ｗ_sn0Δｔ_sn≦０ ・・・(19)
で与えられる。
【００４９】
更にパネル構造体と各補強材との重量比をｖ_p：ｖ_s1：・・・：ｖ_snとおくと、
上式(19)から総重量軽減のための条件式、
ｖ_p(Δｔ_p/ｔ_p0)＋ｖ_s1(Δｔ_s1/ｔ_s10)＋・・・＋ｖ_sn(Δｔ_sn/ｔ_sn0) ≦０ ・・・(20)
を得ることができる。
【００５０】
ここで、上述した実施例について、条件式(17),(20)を用いて剛性を増大させるための条件と総重量を軽減するための条件を求める。この場合、補強材８は１本だけであるため、式(17),(20)において補強材に関する項は、添字＝ｓ１の項のみとする。
先ず、アウタパネル２の荷重分担率ｙ_p＝１−ｙ、ｍｐ＝ｎ＝２．３、変更前の板厚ｔ_p0＝０．７８、変更板厚ｔ_p＝０．６８を式(17)に代入する。
【００５１】
また、同式(17)に補強材８の荷重分担率ｙ_s＝ｙ、ｍｓ１＝ｍ＝１．２、変更前の板厚ｔ_s10＝ｔ_s0、変更板厚ｔ_s1＝ｔ_s＋Δｔ_s1＝２ｔ_s0を代入すると、全体の剛性を増加させるための条件として、
ｙ＞ ０．１７３
を得ることができる。
【００５２】
また、条件式(20)に
ｔ_p0＝０．７８，Δｔ_p＝−０．１
ｔ_s10＝ｔ_s0，Δｔ_s1＝Δｔ_s＝ｔ_s0
の構造パラメータを代入すると、式(20)は、
ｖ_p(Δｔ_p/ｔ_p0)＋ｖ_s(Δｔ_s/ｔ_s0) ≦ ０ 更に、
(Δｔ_p/ｔ_p0)＋(ｖ_s/ｖ_p)・(Δｔ_s/ｔ_s0) ≦ ０ ・・・(21)
として表され、上式(21)の左辺の値は、
左辺＝−０．１２８＋０．０５＝−０．７８
であるから、上述の実施例が軽量化の条件を満たしていることを確認することができる。
【００５３】
なお、実施例のように補強材８とアウタパネル２との重量比をｗ：１としている場合、上式(21)において、
ｖ_s/ｖ_p＝ｗ
であるから、同式(21)は、
(Δｔ_p/ｔ_p0)＋ｗ(Δｔ_s/ｔ_s0) ≦ ０ ・・・(22)
として表されるので、上式(21)から
Δｔ_p/ｔ_p0≧Δｔ_s/ｔ_s0・ｗ ・・・(23)
を得ることができ、この結果はドアパネルの供試例において述べた条件式(3)に合致する。
【００５４】
以上より、本発明を例えばトラックドア１のアウタパネル２の張り剛性に供試した場合にあっては、その初期剛性を所望に確保するべく補強材８の配置を決定することができる。そして、荷重に対する変形量が充分に大きい領域において、補強材８の荷重分担率が例えば２０％程度にまで増大するとき、アウタパネル２の板厚を低減する一方で、補強材８の板厚を増加する構造変更を行うことにより、総重量の低減と剛性の増加（あるいは確保）の条件を同時に満足するための手法が提供される。
【００５５】
なお、実施例ではパネル構造体及び補強材の構造的な諸元として板厚を用いており、それぞれ構造変更に際して板厚を増減するものとしているが、補強材の構造的な変更として例えば、断面形状の変更やその材料の変更等により剛性増大を実現してもよい。
また、本発明は実施例において供試したトラックドア１以外のパネル構造体だけでなく、例えば、バスのエンジンドアや乗用車のトランクリッド、エンジンフード等においても適用可能である。
【００５６】
【発明の効果】
本発明のパネル構造体の補強材配設方法（請求項１）によれば、既存の張り剛性を損なうことなく総重量の最小化を図ることができ、また、更なる剛性の増大をも実現可能である。
また、条件式を用いた補強材配設方法（請求項２）によれば、複数本の補強材を用いたパネル構造体の張り剛性確保に関し、その最適な配置と重量最適化のための各部材の板厚を正確且つ容易に設定することができる。
【図面の簡単な説明】
【図１】本発明の実施例に供試されるトラックドアの斜視図である。
【図２】補強材の配置プランの例と、各プラン毎の近似モデル及びその初期剛性の比較を示すマトリクスである。
【図３】トラックドアの張り剛性を示した荷重−変位線図である。
【図４】実施例において剛性確保の確認を行うための荷重−変位線図である。
【符号の説明】
１ トラックドア
２ アウタパネル
８ 補強材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for securing reinforcement rigidity by arranging a reinforcing material on a panel structure, and in particular, determining an optimal arrangement of the reinforcing material on the panel structure and determining an optimal structural specification of these members. The present invention relates to a method for arranging a reinforcing member of a panel structure for setting.
[0002]
[Prior art]
For example, Japanese Patent No. 2962107 discloses a technique for disposing a reinforcing material at an optimal position in order to ensure the desired rigidity of the panel structure. In this known arrangement method, the load sharing of the panel structure and the reinforcing material is obtained for loads that increase sequentially, and the reinforcing material is arranged at the optimum position of the panel structure based on the obtained load sharing. More specifically, when the load is sequentially increased at the load point, each strain energy is given as a function of the displacement at the load point from the strain at each point of the panel structure and the reinforcing material and the sequential increment of the stress. By partially differentiating the function with displacement, each load sharing can be obtained.
[0003]
For example, when a publicly known reinforcing material arrangement method is applied to a truck door panel, various reinforcing material arrangement patterns (vertical reinforcing material, horizontal reinforcing material, vertical and horizontal reinforcing material, etc.) are applied to the outer panel. If the load sharing becomes clear, the most advantageous arrangement for securing the rigidity of the outer panel can be easily determined.
[0004]
[Problems to be solved by the invention]
By the way, when the reinforcing material is arranged on the panel structure as described above to secure the tension rigidity and at the same time to minimize the total weight, a clear technical method is not always obtained from the known arrangement method. is not. Therefore, in the above door panel test example, when trying to reduce the weight by structurally changing the door panel and the reinforcing material, for example, the rigidity after the structural change is based on the data of the tension rigidity accumulated in the past. Whether it is sufficient or not is evaluated predictively, and in each case, whether the structural changes of the door panel and the reinforcing material are good or bad is judged empirically.
[0005]
Therefore, in the present invention, in view of the above-described problems, there is provided a reinforcing material arranging method for a panel structure that can specifically realize the minimization of the total weight in addition to the optimal arrangement of the reinforcing material based on the load sharing. The purpose is to provide.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the method for disposing a reinforcing member for a panel structure according to the present invention (claim 1), when the load sequentially increases from 0 at a predetermined load point of the panel structure, The arrangement of the reinforcing material is determined so as to ensure the rigidity of the body as desired (arrangement step). At this time, while obtaining the load sharing of the panel structure and the reinforcing material for the load, while the proportion of the load sharing of the reinforcing material in the total load is larger than the weight ratio of the reinforcing material to the panel structure, When structural changes are made to the panel structure to reduce the weight, the conditions for reducing the total weight of the panel structure and the reinforcing material, and structural changes to the reinforcing material, the rigidity is increased. In order to satisfy the conditions for ensuring the rigidity of the panel structure and the reinforcing material as a whole, the structural specifications of the panel structure and the reinforcing material are respectively set (specification setting step). .
[0007]
In other words, the tension rigidity of the panel structure can be usually analyzed based on the relationship between the load and the displacement. The tension stiffness is analyzed separately for the stiffness (initial stiffness) in Fig. 2 and the stiffness when the deformation amount is larger than the initial deformation. In this case, when a load increasing sequentially from 0 is applied to a predetermined load point of the panel structure with the reinforcing material attached, the initial rigidity depends on the arrangement of the reinforcing material and the rigidity of the panel structure alone. Determined. On the other hand, in the deformation region exceeding the region of the initial deformation based on the initial rigidity, the overall rigidity, that is, the total load and the displacement are shared by the panel structure and the reinforcing material.
[0008]
Based on the results of the rigidity analysis as described above, the present invention analytically determines the optimal placement of the reinforcing material to ensure the desired initial rigidity of the panel structure, and loads the panel structure and the reinforcing material. The optimization (minimization) of the total weight can be realized from the two viewpoints of the sharing ratio and the weight ratio between these members. And after setting the optimal arrangement | positioning of a reinforcing material and the structural specification of each member through the above-mentioned arrangement | positioning process and item setting process, a reinforcing material is finally arrange | positioned to a panel structure.
[0009]
Specifically, in the region of the initial deformation of the panel structure described above, the reinforcing material has extremely high rigidity, and the load sharing is extremely small. For this reason, for example, in the analysis model of the panel structure body, the joint portion between the approximate rectangular flat plate model and the reinforcing material can be regarded as a support, and the load point is set at the center of the portion partitioned by the reinforcing material. . When the initial rigidity of the rectangular flat plate in this case is obtained by theoretical solution or FEM analysis, the initial rigidity of the partitioned rectangular flat plate is determined by the length of the short side, and the area of the partitioned portion is the same. It becomes clear that it is more rigidly advantageous to have a more elongated shape. Therefore, the arrangement of the reinforcing material for securing the initial rigidity is optimally arranged along the longitudinal direction of the panel structure. For example, in the case of a horizontally long rectangular panel, the horizontal reinforcing material is more preferable than the vertical reinforcing material. It can be said that this is an advantageous arrangement.
[0010]
On the other hand, in the large deformation region, the load sharing of the reinforcing material increases, and the ratio of the load sharing of the reinforcing material to the total load (= total load sharing) increases to a level that greatly exceeds the weight ratio. In this case, if the rigidity of the reinforcing member is increased, the overall rigidity is ensured and the total weight is reduced as a result of making changes to the structure of these members to reduce the weight of the panel structure. The structural specifications after the change can be set as the formal specifications of each member.
[0011]
On the other hand, in the reinforcing material arranging method of the panel structure according to the present invention (Claim 2), by applying the load sharing ratio of the panel structure and the reinforcing material and the structural parameters thereof to the two conditional expressions, The optimal arrangement of the n reinforcing members and the thicknesses of the reinforcing members and the panel structure can be set at the same time.
Specifically, with respect to a load that sequentially increases from 0 at a predetermined load point of the panel structure with at least one beam-shaped reinforcing member attached to the panel structure of the main member. Load sharing P of panel structure_p0And load sharing P of each reinforcing material_s10, ..., P_sn0, And calculate the total load sharing P₀, This total load sharing P₀Each load sharing P_p0, P_s10, ..., P_sn0The percentage of y_p, Y_s1, ..., y_snAnd
[0012]
Also, the thickness of the panel structure and each reinforcing material is t_p0, T_s10, ..., t_sn0And the change plate thickness when the structure of the panel structure and the reinforcing material is changed by increasing or decreasing each plate thickness is t_p, T_s1, ..., t_snAnd
here,
P₀= P_p0+ P_s10+ ... + P_sn0
Is the total load sharing (total load) in the reference state before the structure change described above, but the increase / decrease load share of the panel structure to be increased / decreased according to the structure change is P_pAlso, increase / decrease load sharing of each reinforcing material is P_s1, ..., P_snThen,
P = P_p+ P_s1+ ... + P_sn
Is the total load sharing that can be borne by all members when the structure is changed.
[0013]
At this time, the relationship between each increase / decrease load sharing after the structure change and each load sharing before the structure change is the following equation with each plate thickness and each change plate thickness as a structural parameter:
P_i= P_i0(t_i/ t_i0)^mi= Y_iP₀(t_i/ t_i0)^mi
Can be represented by
Here, the difference between each change plate thickness and each plate thickness before the change is Δt_p, Δt_s1, ... Δt_snThe weight ratio between the panel structure and each reinforcing material is v_p: V_s1: ...: v_snThe relationship between each plate thickness and its changed plate thickness, and the relationship between each plate thickness and its difference is the following equation:
y_p(t_p/ t_p0)^mp+ Y_s1(t_s1/ t_s10)^ms1+ ... + y_sn(t_sn/ t_sn0)^msn ≧ 1 and
v_p(Δt_p/ t_p0) + V_s1(Δt_s1/ t_s10) + ... + v_sn(Δt_sn/ t_sn0) ≦ 0
Satisfying the conditions at the same time is a condition for achieving both rigidity securing and total weight reduction. Therefore, the rigidity of the panel structure and each reinforcing material is determined by setting the actual plate thickness of the panel structure and each reinforcing material to the above-mentioned changed plate thickness so that these conditional expressions are satisfied at the same time. It is possible to easily optimize the weight without loss.
[0014]
According to the arrangement method using the above conditional expression, first, in the current appropriate reinforcement arrangement for the panel structure, the thickness of each i member is set to the initial thickness t._i0And Further, mi in the conditional expression is determined from the single characteristic (load-displacement) of the i member (procedure 1).
Next, the load sharing ratio y of each i member_i= P_i0/ P₀And weight ratio v_iAnd change thickness t_iIs set (procedure 2). At this time, the plate thickness is reduced for panel structures having a large weight ratio compared to the load sharing ratio, while the plate thickness is increased for a reinforcing material having a large load sharing ratio compared to the weight ratio. It is preferable to do.
[0015]
Structure parameter t_i0, T_iAre determined, it is determined whether or not the above two conditional expressions are satisfied simultaneously with these plate thicknesses (procedure 3). If this determination result is satisfactory, the changed thickness t after the structural change with respect to the current arrangement of the reinforcing material_iCan be adopted. On the other hand, if the conditional expression is not satisfied, the change of the thickness t_iIs reset (procedures 2 and 3).
[0016]
By repeatedly executing the above-described procedure, it is possible to set the optimal arrangement of the reinforcing material and the plate thickness of each member that simultaneously satisfy the two conditional expressions. The set plate thickness t_iIf the practical target performance and weight of the panel structure are not obtained in step 1, the current reinforcing material arrangement and plate thickness after the structural change once performed are reset as the initial state, and a new plate thickness t_i0= T_iThen, steps 2 and 3 may be executed again.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
In the panel structure reinforcement method according to the present invention, for example, for a door panel of a truck vehicle, the reinforcement material is arranged at the optimum position of the outer panel, and the plate thickness which is the structural specification of each of these members is set optimally. In addition, an embodiment can be taken as a method for securing rigidity and reducing the weight of the door panel.
[0018]
As shown in FIG. 1, the track door 1 is configured with an outer panel 2 and an inner panel 3 attached to each other. The outer half of the outer panel 2 has its upper half formed as a window frame 4, while its lower half is formed as a door frame (door frame) 6. Further, the door frame 6 is added along the lower end of the side window, This additional portion extends in the transverse direction of the outer panel 2.
[0019]
In such an outer panel 2, a reinforcing material 8 is attached to the inner surface of the outer panel 2 in order to ensure the tension rigidity of the portion surrounded by the window frame 4 and the door frame 6. The reinforcing material 8 is, for example, the inner surface of the outer panel 2. It is glued to. The reinforcing member 8 has a beam shape, and its structure is formed, for example, from a flat plate shape into a cross-sectional hat shape in order to ensure necessary rigidity.
[0020]
【Example】
Hereinafter, the track door 1 of FIG.
In the present embodiment, first, the initial rigidity when a load that sequentially increases from 0 is applied to the outer panel 2 in a state where the reinforcing member 8 is attached to the outer panel 2 is analyzed. At this time, since the molding curvature of the outer panel 2 is small, the rigidity analysis can be approximated by a rectangular flat plate model.
[0021]
FIG. 2 shows examples of various arrangement plans of the reinforcing material 8 and approximate models for each plan. The approximate model of the rectangular flat plate sets the ratio of the length of the short side to the long side, that is, the aspect ratio, about 1: 2 in accordance with the actual size of the outer panel 2.
First, in the arrangement plan of the vertical reinforcing material, the reinforcing material 8 is arranged in the vertical direction at a substantially central position as seen in the lateral direction of the outer panel 2. A load point F is set at the center position of one of the portions of the outer panel 2 partitioned into two by the reinforcing material 8.
[0022]
In the horizontal reinforcing material arrangement plan, the reinforcing material 8 is arranged along the longitudinal direction of the outer panel 2 at a substantially central position when viewed in the vertical direction. A load point E is set at the center position of the upper part of the outer panel 2 partitioned by the reinforcing material 8.
In the arrangement plan of the vertical / horizontal reinforcing material, the vertical reinforcing material and the horizontal reinforcing material are combined and arranged. In this case, the outer panel 2 is divided into four, and the load point D is set at one of the upper central positions of the four sections. In the approximate model, it is not necessary to consider the difference between the sections.
[0023]
When the load is sequentially increased from 0 at each of the load points F, E, and D described above, the rigidity of the reinforcing material 8 is higher than that of the outer panel 2 in the initial stage of the increase. In the rigidity analysis used, the joint portion between the outer panel 2 and the reinforcing material 8 can be regarded as support. Under these conditions, a theoretical solution of the initial stiffness is obtained for each arrangement plan and compared.
[0024]
FIG. 2 shows the stiffness ratio k of the theoretical solution for the initial stiffness obtained for each arrangement plan.₀, And the standard stiffness (k₀= 1.0), the rigidity ratio k is used for the lateral reinforcement.₀= 2.75, and for longitudinal and lateral reinforcements, the stiffness ratio k₀= 2.81.
The following is clear from the above-mentioned rigidity comparison.
[0025]
That is, it can be said that both the horizontal reinforcing member and the vertical / horizontal reinforcing member arrangement plan are advantageous to the extent of nearly three times the initial rigidity in comparison with the longitudinal reinforcing member arrangement plan. On the other hand, when the arrangement plan of these horizontal reinforcing members is compared with the arrangement plan of the vertical and horizontal reinforcing members, the presence or absence of the reinforcing members 8 arranged in the vertical direction hardly affects the initial rigidity. Moreover, in both these arrangement plans, although the length of the long side (horizontal direction) of the divided rectangular flat plate differs, the length of the short side is the same. This means that the initial rigidity in the partitioned part of the rectangular flat plate is determined depending on the length of the short side. In this case, in the part of the same area, it has a more elongated shape. One is considered to be more advantageous in securing the initial rigidity. Therefore, in order to ensure the initial rigidity of the outer panel 2, it was confirmed that the arrangement plan of the horizontal reinforcement (vertical / horizontal reinforcement) is more preferable than the arrangement plan of the vertical reinforcement (arrangement process).
[0026]
In addition, although the result of the initial stiffness ratio at the time of performing linear FEM analysis about each arrangement plan is also shown in FIG. 2, the joint part with the reinforcing material is regarded as support in the theoretical solution as described above. From this, it is presumed that the value of the stiffness ratio is larger than in the case of FEM analysis. However, since there is no extreme divergence between the FEM analysis results and the theoretical solution analysis results, the relationship between the placement of the reinforcing material and the initial stiffness is as described above by comparing the rigidity based on the theoretical solution. It can be explained.
[0027]
Next, analysis of the weight optimization of the door panel 1 is performed along with the placement of the reinforcing member 8 on the outer panel 2 described above.
It was clarified that the initial rigidity of the outer panel 2 is determined only by the arrangement of the reinforcing member 8 and is hardly influenced by the member rigidity of the reinforcing member 8. Here, the initial stiffness is the stiffness of the outer panel 2 at the initial stage of the increase in load. In the deformation region exceeding the region of initial deformation based on such initial stiffness, the load and displacement are shared by the outer panel 2 and the reinforcing material 8. Is done.
[0028]
FIG. 3 represents the tension rigidity of the outer panel 2 by a load-displacement diagram, and the curve indicated by the solid line in the diagram indicates the load that increases sequentially at the load point (expressed as a ratio to the maximum load Pmax). Yes. The maximum load Pmax is set to, for example, the maximum value of the load assumed to be applied to the outer panel 2 in practical use of the truck.
Here, when a load is applied in a state where the reinforcing material is attached to the panel structure, the principle that the load is shared by the panel structure and the reinforcing material and the entire displacement is shared by these two members is already It is known in the above-mentioned Japanese Patent No. 2962107.
[0029]
Based on such energy principle, the load sharing of the outer panel 2 and the reinforcing member 8 is obtained respectively, and is superimposed on the load-displacement diagram of FIG. 3 to show the load sharing of the outer panel 2 (expressed as a ratio to the sequential load). Is represented by a broken line in the figure, and the load sharing of the reinforcing member 8 is represented by a one-dot chain line. In addition, since there is almost no load sharing of members (for example, the inner panel 3, an adhesive agent, etc.) other than the outer panel 2 and the reinforcing material 8, the illustration is omitted here.
[0030]
As described above, the load sharing of the reinforcing member 8 is extremely small in the region of initial deformation. Therefore, in the region of initial deformation, the curve representing the load level and the curve representing the load sharing of the outer panel 2 are substantially matched. . On the other hand, as the entire amount of deformation increases beyond the region of initial deformation, the load sharing of the reinforcing member 8 gradually increases, and particularly in the region where the amount of deformation is large, it is represented by a two-dot difference line in the figure. In addition, the ratio of the load sharing of the reinforcing material 8 to the total load sharing, that is, the load sharing ratio reaches a level exceeding 20%.
[0031]
On the other hand, in terms of the weight ratio between the outer panel 2 and the reinforcing material 8, in the case of the present embodiment, the weight ratio of the reinforcing material 8 is about 5% in the arrangement of the lateral reinforcing material. The load sharing of the material 8 greatly exceeds the weight ratio.
The inventor of the present invention pays attention to the fact that a certain margin is secured in the initial rigidity of the outer panel 2 by arranging the reinforcing member 8 in a panel structure such as a door panel of a truck, While reducing the plate thickness of the outer panel 2 to reduce the weight, increasing the plate thickness of the reinforcing member 8 and increasing the load sharing is an effective means for ensuring both the rigidity of the tension and the weight reduction. Confirm that there is.
[0032]
In this embodiment, for example, the reference plate thickness of the outer panel 2 is t_p0= 0.78 mm, the thickness (change plate thickness) of the outer panel 2 is t_p= 0.68 mm and the reference plate thickness t of the reinforcing material 8_s0Is twice the thickness (changed thickness t_s= 2t_s0) And structural changes were made to these components.
Table 1 shows the result of the structure change according to this example. In addition, all the weights are shown in a weight ratio based on the weight at the reference plate thickness of the outer panel 2 (= 1).
[0033]
[Table 1]

[0034]
As apparent from Table 1, the effect of weight reduction by reducing the plate thickness of the outer panel 2 exceeds the weight increase by increasing the plate thickness of the reinforcing member 8, so that the weight ratio of the outer panel 2 and the reinforcing member 8 as a whole is 7. A weight reduction of 4% can be achieved.
Furthermore, with reference to FIG. 4, confirmation of rigidity is confirmed in the load-displacement diagram accompanying the structural change of the above-described embodiment.
[0035]
Characteristics shown by solid lines in the figure (t_p0= 0.78, t_s0) Shows the rigidity at the reference plate thickness before the structural change. On the other hand, when the structural change of the embodiment is performed, the rigidity is a characteristic (t_p= 0.68, 2t_s0), But the initial stiffness is the initial stiffness k before the structural change.₀It is confirmed that the rigidity in the large deformation region is sufficiently secured. This is based on the effect that the rigidity of the reinforcing member 8 is relatively increased by increasing the plate thickness, and the load sharing of the reinforcing member 8 is increased accordingly.
[0036]
Moreover, even if the plate thickness of the outer panel 2 is reduced, the result that the initial rigidity is hardly reduced is that the above-described reinforcing material 8 is arranged to provide a margin for the initial rigidity of the outer panel 2. It is also useful as a backing for.
FIG. 4 shows the thickness of the outer panel 2 as a reference thickness t as an example of a structural change other than the embodiment._p0To reduce only the plate thickness of the reinforcing material 8 in half (t_p0= 0.78, 0.5t_s0) Is indicated by a broken line, and only the thickness of the reinforcing member 8 is doubled (t_p0= 0.78, 2t_s0) Is indicated by a two-dot chain line. As is clear from these modified examples, it is recognized that increasing the structural rigidity of the reinforcing member 8 by increasing the plate thickness is more effective for ensuring the rigidity as a whole in the region where the amount of deformation is large. .
[0037]
Accordingly, in this embodiment, the structural specifications of the outer panel 2 and the reinforcing member 8, for example, the plate thickness thereof are set so as to satisfy the following two conditions simultaneously (specification setting step).
(1) The total weight including the reinforcing material 8 is relatively reduced by structural weight reduction such as reduction of the thickness of the outer panel 2.
(2) The total load sharing when the load sharing of the outer panel 2 and the reinforcing member 8 is totaled is relatively increased due to an increase in structural rigidity such as an increase in the thickness of the reinforcing member 8.
[0038]
For example, even if the thickness of the outer panel 2 is reduced and the weight is reduced, if the total weight is increased by the increase in the thickness of the reinforcing member 8, the structural change is made under the condition (1) above. Not satisfied. Further, even if the plate thickness of the reinforcing member 8 is increased to increase the rigidity, if the overall rigidity is reduced by the reduction of the plate thickness of the outer panel 2, the structural change is as described in (2) above. The condition is not satisfied. In these cases, it is necessary to change the thickness again to satisfy the two conditions simultaneously.
[0039]
In addition, the inventor of the present invention provides a conditional expression using the plate thicknesses of the outer panel 2 and the reinforcing material 8 as structural parameters as evaluation criteria for simultaneously satisfying the above conditions (1) and (2). Yes. The conditional expression is derived by the following procedure.
Thickness t of the outer panel 2 and the reinforcing material 8 in a reference state appropriately selected in advance_p0, T_s0For the structural changes, the thickness of the change is t_p, T_sAnd Reference thickness t before structural change_p0, T_s0For example, according to the vehicle grade and specifications of the truck, it is sufficient to set the plate thickness to ensure the normally required door rigidity.
[0040]
Δt is the thickness reduction of the outer panel 2_p, Δt is the thickness increase of the reinforcing material 8_sThen, these increases and decreases (difference)
Δt_p= T_p0-T_p, Δts = t_s-T_s0  ... (1), (2)
It is represented by
Next, when the weight ratio between the reinforcing member 8 and the outer panel 2 is w: 1, the condition for reducing the total weight is expressed by the following equation (3).
[0041]
Δt_p/ t_p0> Δt_s/ t_s0・ W ・ ・ ・ (3)
Further, the load sharing P between the outer panel 2 and the reinforcing material 8 in the reference state before the structure change._p0, P_s0If the structure of these members is changed, the increase / decrease load sharing to be increased / decreased is P_p, P_sAnd At this time, if the structural parameters of the outer panel 2 and the reinforcing material 8 are expressed by their respective plate thicknesses, these structural parameters and the increase / decrease load sharing P_p, P_sCan be expressed by the following equations (4) and (5).
[0042]
P_p/ P_p0= (T_p/ t_p0)ⁿ, P_s/ P_s0= (T_s/ t_s0)^m  ... (4), (5)
On the other hand, the total load sharing that can be borne by all members when the structure is changed is P, and the load sharing rate of the outer panel 2 and the reinforcing material 8 is y._s, Y_p, Z (≡1-y)_s-Y_p)
P_p+ P_s+ P₁+ P₂+ ... + P_n= P (6)
P₁+ P₂+ ... + P_n= P_Ten+ P₂₀+ ... + P_n0= ZP₀  ... (7)
As a condition for relatively increasing the rigidity when the structure is changed, P> P₀The thickness condition for satisfying The load sharing ratio y_p, Y_sAre respectively y_p= P_p0/ P₀, Y_s= P_s0/ P₀Defined by
[0043]
Here, from the above formulas (4), (5) and the definition of load sharing ratio,
P_p= P_p0(T_p/ t_p0)ⁿ= Y_pP₀(T_p/ t_p0)ⁿ  ... (8)
P_s= P_s0(T_s/ t_s0)^m= Y_sP₀(T_s/ t_s0)^m  ... (9)
Therefore, the above condition is given by
y_pP₀(T_p/ t_p0)ⁿ+ Y_sP₀(T_s/ t_s0)^m+ ZP₀> P₀···(Ten)
The above formula (10) is further arranged and P₀If you delete
y_p(T_p/ t_p0)ⁿ+ Y_s(T_s/ t_s0)^m+ Z> 1 (11)
It is. Here, it is assumed that the entire load is shared by the outer panel 2 and the reinforcing material 8_p+ Y_s= 1, then y_s= Y, y_p= 1−y, z = 0, equation (11) is
(1-y) ・ (t_p/ t_p0)ⁿ+ Y (t_s/ t_s0)^m> 1 (12)
It is represented by Therefore, for example, the above formulas (3) and (12) are provided as conditional expressions for simultaneously satisfying the total weight reduction and the securing of the tension rigidity.
[0044]
Also, by solving the left side of Equation (12) = 1,
y₀= {1- (t_p/ t_p0)ⁿ} / {(T_s/ t_s0)^m-(T_p/ t_p0)ⁿ} ···(13)
Load sharing ratio after structural change y₀If y is already defined, y> y₀Is a condition for securing the rigidity.
The above is a conditional expression for the embodiment. For example, in the case where a plurality of reinforcing members 8 are arranged as in the above-described arrangement plan of the vertical and horizontal reinforcing materials, the following general expression should be used. Can do.
[0045]
Here, it is assumed that the conditions regarding the panel structure and its reinforcing material are not limited to the door panel of the truck. That is, a load that increases sequentially from 0 is applied at the load point of the panel structure with n (at least one) reinforcing members attached to the panel structure in the reference state before the structure change. Obtain the load sharing of the panel structure and each reinforcing material against this load, and calculate the load sharing of the panel structure P_p0The load sharing of each reinforcing material (s1 to sn) is P_s10, ..., P_sn0And
[0046]
Here, the total load sharing in the reference state, that is, the total load sharing P₀Is
P₀= P_p0+ P_s10+ ... + P_sn0  ···(14)
It is. In this case, since the applied total load is shared by the panel structure and all the reinforcing materials, the total load sharing P₀And the total load is the same.
On the other hand, when the load sharing of the panel structure and each reinforcing material increases or decreases due to a structural change, the increased or decreased load sharing after the change is P_p, P_s1, ..., P_nThen, the total load P that can be borne after the structural change is
P = P_p+ P_s1+ ... + P_sn  ... (15)
It is.
[0047]
For example, when the structure is changed by increasing / decreasing the plate thickness of each member, the increase / decrease load sharing of each member after the change can represent the plate thickness as a structural parameter. Here, the thickness of the panel structure of each member in the reference state is t_p0, The thickness of each reinforcing material is t_s10, ..., t_sn0Also, the thickness after the change is t_p, T_s1, ..., t_snThen, increase / decrease load sharing P of i member_iIs
P_i= P_i0(t_i/ t_i0)^mi= Y_iP₀(t_i/ t_i0)^mi  ... (16)
It is represented by Note that i = p, s1,..., Sn.
[0048]
Therefore, from the above formulas (15) and (16), a conditional formula for increasing the total load that can be borne after the structural change,
y_p(t_p/ t_p0)^mp+ Y_s1(t_s1/ t_s10)^ms1+ ... + y_sn(t_sn/ t_sn0)^msn≧ 1 ・ ・ ・ (17)
Can be obtained.
In addition, the unit weight of the i member is W_i0As the weight per unit plate thickness,
w_i0= W_i0/ t_i0  ... (18)
In addition, the increase / decrease in the plate thickness of each member is Δ_tp, Δt_s1, ..., Δt_snThen, the conditions for reducing the total weight that should be satisfied at the same time as the increase in the total load sharing are:
w_p0Δt_p+ W_s10Δt_s1+ ... + w_sn0Δt_sn≦ 0 (19)
Given in.
[0049]
Furthermore, the weight ratio between the panel structure and each reinforcement is v_p: V_s1: ...: v_snAfter all,
Conditional formula for total weight reduction from the above formula (19),
v_p(Δt_p/ t_p0) + V_s1(Δt_s1/ t_s10) + ... + v_sn(Δt_sn/ t_sn0) ≦ 0 (20)
Can be obtained.
[0050]
Here, for the above-described embodiment, the conditions for increasing the rigidity and the conditions for reducing the total weight are obtained using the conditional expressions (17) and (20). In this case, since there is only one reinforcing material 8, the term relating to the reinforcing material in the equations (17) and (20) is only the term of subscript = s1.
First, the load sharing ratio y of the outer panel 2_p= 1-y, mp = n = 2.3, thickness t before change_p0= 0.78, change thickness t_p= 0.68 is substituted into equation (17).
[0051]
In addition, the load sharing rate y of the reinforcing material 8_s= Y, ms1 = m = 1.2, thickness t before change_s10= T_s0, Change thickness t_s1= T_s+ Δt_s1= 2t_s0Substituting, as a condition to increase the overall stiffness,
y> 0.173
Can be obtained.
[0052]
Conditional expression (20)
t_p0= 0.78, Δt_p= -0.1
t_s10= T_s0, Δt_s1= Δt_s= T_s0
(20) becomes
v_p(Δt_p/ t_p0) + V_s(Δt_s/ t_s0) ≦ 0
(Δt_p/ t_p0) + (V_s/ v_p) ・ (Δt_s/ t_s0) ≦ 0 (21)
The value on the left side of the above equation (21) is
Left side = −0.128 + 0.05 = −0.78
Therefore, it can be confirmed that the above-described embodiment satisfies the conditions for weight reduction.
[0053]
When the weight ratio between the reinforcing member 8 and the outer panel 2 is w: 1 as in the embodiment, in the above equation (21),
v_s/ v_p= W
Therefore, the equation (21) is
(Δt_p/ t_p0) + W (Δt_s/ t_s0) ≦ 0 (22)
From the above formula (21)
Δt_p/ t_p0≧ Δt_s/ t_s0・ W ・ ・ ・ (23)
This result agrees with the conditional expression (3) described in the test example of the door panel.
[0054]
From the above, when the present invention is used for the tension rigidity of the outer panel 2 of the track door 1, for example, the arrangement of the reinforcing member 8 can be determined so as to ensure the initial rigidity as desired. When the load sharing ratio of the reinforcing material 8 increases to, for example, about 20% in a region where the deformation amount with respect to the load is sufficiently large, the thickness of the reinforcing material 8 is increased while the thickness of the outer panel 2 is reduced. By changing the structure, a method for simultaneously satisfying the conditions of reducing the total weight and increasing (or securing) the rigidity is provided.
[0055]
In the embodiment, the plate thickness is used as a structural specification of the panel structure and the reinforcing material, and the plate thickness is increased or decreased at the time of changing the structure. The rigidity may be increased by changing the shape or the material thereof.
Further, the present invention is applicable not only to panel structures other than the truck door 1 used in the embodiment, but also to, for example, bus engine doors, passenger car trunk lids, engine hoods, and the like.
[0056]
【The invention's effect】
According to the reinforcing material arranging method of the panel structure of the present invention (Claim 1), the total weight can be minimized without impairing the existing tension rigidity, and the rigidity can be further increased. Is possible.
Further, according to the reinforcing material arranging method using the conditional expression (Claim 2), each of the optimal arrangement and weight optimization for securing the rigidity of the panel structure using a plurality of reinforcing materials. The plate thickness of the member can be set accurately and easily.
[Brief description of the drawings]
FIG. 1 is a perspective view of a truck door used in an embodiment of the present invention.
FIG. 2 is a matrix showing an example of a reinforcing material arrangement plan, an approximate model for each plan, and a comparison of its initial stiffness.
FIG. 3 is a load-displacement diagram showing the tension rigidity of the track door.
FIG. 4 is a load-displacement diagram for confirming rigidity in the embodiment.
[Explanation of symbols]
1 Truck door
2 Outer panel
8 Reinforcing material

Claims (2)

With the beam-shaped reinforcement attached to the panel structure of the main member, the rigidity of the panel structure is desired at the initial stage of the increase of the load against the load that gradually increases from 0 at a predetermined load point of the panel structure. An arrangement process for deciding the arrangement of the reinforcing material to ensure;
While determining the load sharing of the panel structure and the reinforcing material with respect to the load, when the ratio of the load sharing of the reinforcing material to the load is larger than the weight ratio of the reinforcing material to the panel structure, the structure of the panel structure The conditions for reducing the total weight of the panel structure and the reinforcing material by reducing the overall weight, and the conditions for securing the overall rigidity of the panel structure and the reinforcing material by increasing the structural rigidity of the reinforcing material. A method for arranging a reinforcing material for a panel structure, comprising: a specification setting step for setting structural specifications of the panel structure and the reinforcing material so as to satisfy at the same time. The load of the panel structure against a load that sequentially increases from 0 at a predetermined load point of the panel structure with at least one beam-shaped reinforcing member attached to the panel structure of the main member sharing P _p0 and load distribution P _s10 of each stiffener, ..., together with obtaining the P _sn0 respectively, the total load sharing to the sum of these load distribution P _0, each load distribution P occupied in the total load sharing P _{0 p0,} P _s10, ···, the ratio of P _sn0 and _{y p, y s1, ···,} y sn,
In addition, the plate thickness of the panel structure and each reinforcing material is t _p0 , t _s10 ,..., T _sn0 , and the change plate when the structure of the panel structure and the reinforcing material is changed by increasing or decreasing these thicknesses. the thickness of _{t p, t s1, ···,} t sn, subtracting the Delta] t _p between them and each change thickness wherein each plate thickness, Δt _s1, ··· Δt _sn, the panel structure and the reinforcing material And v _p : v _s1 : ...: v _sn
When the increase / decrease load sharing of the panel structure to be increased / decreased according to the change of the structure is P _p and the increase / decrease load share of each reinforcing material is P _s1 ,..., P _sn , The relationship between each load sharing is the following equation with each plate thickness and each changed plate thickness as a structural parameter:
P _i = P _i0 (t _i / t _i0 ) ^mi = y _i P ₀ (t _i / t _i0 ) ^mi
(Where i = p, s1,..., Sn)
And the relationship between each plate thickness and each change plate thickness, and each plate thickness and each difference is represented by the following equation:
y _p (t _p / t _p0 ) ^mp + y _s1 (t _s1 / t _s10 ) ^ms1 +... + y _sn (t _sn / t _sn0 ) ^msn ≧ 1 and v _p (Δt _p / t _p0 ) + v _s1 (Δt _s1 / t _s10 ) + ... + v _sn (Δt _sn / t _sn0 ) ≦ 0
And determining the arrangement of the reinforcing members on the panel structure so as to satisfy the requirements at the same time, and setting the actual plate thicknesses of the panel structure and the reinforcing members as the respective changed plate thicknesses. Reinforcing material placement method.

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