CN110046433B - Boundary element analysis method based on commercial vehicle whole vehicle parameters - Google Patents

Abstract

The invention discloses a boundary element analysis method based on the parameters of a commercial vehicle, which is characterized by comprising the following steps: 1) applying a regularly changing load; 2) obtaining a damping characteristic curve; 3) weighting the damping characteristic in sections; 4. ) to establish a segmented weighted parameter set; 5) to extract the parameter boundary element; 6) to design the whole vehicle global boundary element. This method can reasonably and accurately design nonlinear damping, improve the accuracy of nonlinear scaling and matching, save development cycle and cost, reduce training cycle, and facilitate the formation of a standard parameter scaling database for models, which is convenient for reducing the same models. vibration design for reference.

Description

A Boundary Element Analysis Method Based on Vehicle Parameters of Commercial Vehicles

technical field

The invention relates to the technology of commercial vehicles, in particular to a boundary element analysis method based on the parameters of the entire commercial vehicle.

Background technique

The ride comfort of commercial vehicles usually seriously affects driving comfort and comfort. Therefore, many companies and vehicle R&D industries have put forward higher requirements for the vibration reduction parameters of the vibration reduction system on commercial vehicles. The vibration damping structure includes: suspension springs, dampers, rubber bushings and leaf springs, etc. Therefore, in order to make the multi-vibration damping and damping structure of the vehicle achieve a better overall adjustment effect, it is theoretically necessary to meet the vibration damping and damping requirements. The vibration damping parameter values of the structure must be matched to the optimal value. However, in the actual vehicle entity, these theoretical optimal values are often difficult to obtain. Often, only the original damping parameter characteristics can be scaled as a whole to obtain An approximation to the optimal value.

In the development stage of the body of commercial vehicles, due to the complexity of driving conditions and the diversification of loads, the damping parameters of the vibration damping components installed on commercial vehicles are often set to nonlinear characteristics. The curve is used to meet the requirements of different damping characteristics under different working conditions or loads. The up and down fluctuation range of the nonlinear damping characteristic value is usually determined by the installation limit conditions of the structure and the property restrictions of the material. In the damping test design software (such as Isight and other software) and the common analysis methods of scientific research institutions, the traditional linear damping optimization method is still used to design the damping, that is, the existing nonlinear characteristic curve is adjusted with a certain scaling factor. The scaling behavior is used to regularly scale the overall characteristic curve value, but the scaling method is symmetrical, and the setting of the scaling range mainly depends on the subjective experience of the designer. Therefore, there is an artificial design effect. Influencing factors, the best design effect cannot be obtained. The design idea of the existing traditional nonlinear damping design method can be set as:

Assuming that the initial nonlinear damping characteristic curve is S ₀ , the scaling factor is C (C=[c ₀ , c ₁ , c ₂ , ... c _i ]), and the design objective is S _i , the traditional nonlinear damping The design method can be expressed as:

S _i =S ₀ (1±c ₀ )(1±c ₁ )(1±c ₂ )...(1±c _i )

where i is the total number of design scalings, c ₀ is the scaling factor based on the original characteristic curve of the product damping, and the scaling factor is determined by the initial load between the upper and lower ends of the shock absorber after the product is installed. Due to the constant change and adjustment of factors such as the late load of the shock absorber, it is necessary to multiply the last design product by a certain proportion to modify the scaling factor (c ₁ , c ₂ ,..., _ci ), and then to the original design product. The nonlinear curve is continuously scaled and corrected to achieve the design purpose of the designer, but since the scaling method is based on the global scaling of the nonlinear characteristic curve as a whole, it is easy to ignore the regional optimal matching, resulting in The design accuracy of damping is poor, and the number of times of scaling is small, and the influence effect between multiple scalings of multi-level load shocks is not considered, so it is easy to cause accidental errors.

For commercial vehicles that have already been sold, when designers adjust the performance of the recovered problem models, due to the wear, deformation and fracture problems of some of the vibration-damping components of the problem models, it is necessary to repair the vibration-damping components. The damping needs to be re-designed and checked. At this time, due to the lack of reference of the design range, the variation range of the scaling factor of the original nonlinear characteristic curve is quite different from the overall variation of the characteristics of the restored nonlinear curve. Therefore, it requires a large maintenance cost, and the design adjustment time is long, which obviously affects the design cycle of the product. In some special cases, due to the limitation of cost and production development, some developers can only use some existing data to simulate the linear damping characteristic curve to replace the nonlinear characteristic in order to simplify the analysis steps for some problem models. curve, which causes a large matching error to a certain extent, and has a large deviation from the theoretical optimization value, which ultimately affects the optimal vibration reduction matching result of the vehicle vibration reduction and damping.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a boundary element analysis method based on the parameters of the entire commercial vehicle in view of the deficiencies of the prior art. This method can reasonably and accurately design nonlinear damping, improve nonlinear scaling and matching accuracy, save development cycle and cost, reduce training cycle, and facilitate the formation of a standard parameter scaling database of the model, which is convenient for reducing the same model. vibration design for reference.

The technical scheme that realizes the object of the present invention is:

A boundary element analysis method based on vehicle parameters of a commercial vehicle, which is different from the prior art, includes the following steps:

1) Apply a regularly changing load: first, install a pressure sensor on the upper port of the vibration-absorbing nonlinear damper to collect the change in load, and at the same time set an upper displacement sensor and a lower displacement sensor on the side wall of the vibration-absorbing nonlinear damper to To detect the displacement change under the action of the load force, in the initial stage of the calibration design, a predetermined value of initial load N ₀ is applied to the upper and lower ports of the vibration damping nonlinear damper, and the size of the initial load N ₀ should be set so that the vibration reduction is not The stress piece on the linear damper senses a clear and obvious pressure, and then the load is gradually increased according to the load interval F ₀ . The increasing load force can be expressed as: N ₀ , N ₀ +F ₀ , N ₀ +2F ₀ , N ₀ +3F ₀ , N ₀ +4F ₀ , N ₀ +5F ₀ ,…,N ₀ +nF ₀ , where the value of n is determined by the limit stress value of the load that the nonlinear damper can bear ;

2) Obtain the damping characteristic curve: under the action of regular load stress, measure the sampling time t of the applied variable load acting on the vibration damping damper, and simultaneously measure the upper displacement sensor and the lower displacement sensor on the side wall of the vibration damping damper The magnitude of the displacement changes after the load is applied. According to the calculation principle of the viscous damping theory, the magnitude of the damping force F _R (t) is proportional to the speed, and the direction is opposite to the speed of the displacement. Assuming that the displacement is y(t), according to the damping force The corresponding relationship between , displacement and time, the stress load signal on the pressure sensor collected on the vibration-damping nonlinear damper and the displacement signal collected by the upper and lower displacement sensors are preprocessed, and the vibration-damping force is further obtained. The time-varying nonlinear damping characteristic curve is used to observe the damping nonlinear change trend. The traditional damping nonlinear curve obtains the nonlinear damping overall characteristic amplification curve and the nonlinear damping overall reduction characteristic curve through the overall scaling method;

3) Piecewise weighting of damping characteristics: According to the nonlinear damping characteristic curve obtained in step 2), for the weighted scaling factor, a piecewise discrete design of nonlinear damping is proposed. The stress load signal on the pressure sensor, the upper displacement sensor and the lower In the process of collecting displacement signals collected by the displacement sensor, it is assumed that in n different successive unit times, the size of the piecewise weighted scaling factors of the nonlinear damping characteristic curve are: [c ₁ ,c ₂ ,c ₃ ,... ,c _n ], then the original nonlinear weighted characteristic curve S ₀ is multiplied by different piecewise weighted scaling factors to obtain the characteristic curve segment [S ₁ , S ₂ , S ₃ ,...S _n-1 ,S _n ], in which, in order to ensure the continuity of the curve after scaling, the damping force data corresponding to the node position of each unit time does not participate in the scaling process, and the curve expression formula obtained after the corresponding overall nonlinear damping weighted scaling is formula (1):

According to the above discretization process, the original nonlinear damping characteristic curve is gradually discretized. In addition, in the value of the piecewise weighted scaling factor, the piecewise weighted scaling factors of the nonlinear damping characteristic curve are mutually exclusive. Interdependent, with arbitrary piecewise weighted scaling factors c _i and c _i+1 for illustration, after applying piecewise weighted scaling factor c _i , the corresponding scaling nonlinear damping characteristic segment is S _i , at this time If the non-damping characteristic amplification factor curve S _(0n-i) ·(1+c _i ) has a better damping effect on the damper than the non-damping characteristic reduction factor curve S _{(0n-i) ·} (1-ci ) , at this time, the secondary segment scaling factor c _i+1 will tend to be corrected in the direction of enlargement, which can be expressed as:

c _i+1 = c _i +ξ _i

where ξ _i is the coefficient of variation of the piecewise scaling factor, and the corresponding equivalent nonlinear damping characteristic curve of c _i+1 can be expressed as:

S ₀ =S _0i+1 ·(1±ci ₊₁ )=S _0i ·(1± _{ci +ξ i )} ;

4) Establish a segmented weighted parameter set: Considering the interaction effect between adjacent segment scaling factors in step 3), separately collecting segment scaling factor and variation coefficient values on each segment can accurately quantify damping characteristics The curve feature is convenient to find the optimal scaling ratio of vibration attenuation under the load of a specific vibration damping mechanism. After collecting the segment scaling factor and variation coefficient value on each segment, the segment weighting parameter set is gradually established and can be expressed as:

S ₁ :S _(0,1) ,c ₁ ,0

S ₂ :S _(0,2) ,c ₂ ,ξ ₂

S ₃ :S _(0,3) ,c ₃ ,ξ ₃

...:...,...,...

S _n-1 :S _(0,n-1) ,c _n-1 ,ξ _n-1

S _n : S _{(0,n) ,} c _n ,ξn

Among them, S _(0,1) ,S _(0,2) ,S _(0,3) ,...,S _(0,n-1) ,S _(0,n) represent the original nonlinear damping characteristics segment, c ₁ , c ₂ , c ₃ ,...,c _n-1 ,c _n represent the piecewise scaling factor of the nonlinear damping characteristic curve, 0,ξ ₂ ,ξ ₃ ,...,ξ _n is Coefficient of variation value of each segment of nonlinear damping characteristic curve;

5) Extraction of parameter boundary elements: After multiplying the original nonlinear damping characteristic curve by the respective piecewise scaling factor and coefficient of variation value, the assumed variation interval can be expressed as [S _0i ·(1+c _i +ξ _i )S _0i ·(1-c _i +ξ _i )], the obtained nonlinear piecewise weighted characteristic curve S ₀ will obtain an optimal parameter value (c _j and ξ _j ) in the corresponding variation interval. The value can make the damping effect of the shock absorber damping tend to be optimal in the scaling process of the i-th segment. Extract and outline these extracted parameter values with virtual curves, and then the optimal parameter boundary element of the overall nonlinear damping characteristic curve can be obtained. The combination of boundary element values can make the overall vibration reduction optimization of the shock absorber tend to be The optimum is also the final design goal of the nonlinear characteristic curve;

6) The global boundary element design of the whole vehicle: After the establishment of the whole segmented weighted parameter set of a single vibration damping and the acquisition of the optimal parameter boundary element, since there are multiple vibration reduction and damping units distributed on the commercial vehicle, and each The load conditions are also different, so the design segment weighting parameters and optimal parameter boundary elements of each vibration damping are also different. Therefore, when designing the angle of the whole vehicle, each independent vibration damping needs to be multiplied by The penalty factor is used to cooperate with other vibration reduction and damping units to achieve the global optimal vibration reduction and damping distribution on the vehicle, which can be expressed as:

S _total =η ₁ ∑(S ₁ ,c ₁ ,ξ ₁ )+η ₂ ∑(S ₂ ,c ₂ ,ξ ₂ )+,...,η _n ∑(S _n ,c _n ,ξ _n )

Among them, η ₁ , η ₂ ,..., η _n are the distribution penalties of each nonlinear damping on the vehicle, S ₁ , S ₂ ,..., _Sn are nonlinear piecewise weighted characteristic curves, c ₁ ,c ₂ ,...,cn _is the piecewise scaling factor of the nonlinear damping characteristic curve, and the coefficient of variation of the piecewise scaling factor of ξ ₁ ,ξ ₂ ,..., _ξn .

The technical solution provides a more reasonable and accurate nonlinear damping design method. By discretely decomposing the original characteristic curve S ₀ , and carrying out characteristic weighting in multiple small ranges, a multi-segment scaling and weighting nonlinear characteristic curve is finally formed. Compared with the original scaling methods of the characteristic curve, the discrete scaling and weighting method is more conducive to making the design of the nonlinear characteristic curve close to the design requirements of the target, and avoids the product scaling caused by the traditional method in a large range. Occurrence of Error The scaling factor used in this technical solution is different in each discrete segment. In the discrete interval of each sub-segment studied, the scaling factor is mainly determined by the sensitivity of parameters to performance. If the effect is obvious, the setting value of the scaling factor is small, so as to carry out a small-scale scaling design. On the contrary, when the effect of parameter changes on the tuning performance is slow, the setting value of the scaling factor should be large, so as to quickly avoid the slow factor range, find the sensitive parameter change range more quickly, and search for the most sensitive parameter range in each range. Scale damping value for optimal nonlinear behavior.

In the determination of the scaling factor benchmark, this technical solution takes the discrete upper segment nonlinear design characteristic curve as the benchmark, rather than the unified design standard as the design criterion, and considers the continuity of the damping scaling and the continuous variation of the load. The resulting interaction effect between damping characteristics improves the accuracy of nonlinear scaling and matching.

The technical solution refers to the deflection characteristics of the body damping curve in the scaling ratio of the scaling factor up and down, and the scaling range of the upper and lower is not the same as that of the traditional method, which avoids the unnecessary nonlinear characteristic design interval of the traditional design method. Analysis, saving development cycle and cost.

This technical solution extracts the optimal design values of each discrete segment, and by outlining the optimal values of each segment, the optimal parameter boundary elements formed by the optimal values of each segment can be gradually obtained, so that the final design result tends to be more Accurate, the design result value is convenient for designers to adjust and reference later, and because the adjustment only needs to consider the characteristic curve value in a small range, and avoids the analysis of the characteristics, thus greatly reducing the adjustment cycle and convenient for companies and companies. The standard parameter scaling database of the model is formed within the R&D institution, which is convenient to provide reference for the vibration reduction design of the same model.

This technical solution takes into account the change trend of the vibration of commercial vehicles during the design process, and continuously performs segmental repairs, so that the modified nonlinear characteristic curves continue to increase in the optimal region of the original small segment nonlinear characteristics, and the nonlinear design results after design make the vehicle The industry is more credible and practical for model tuning, reducing development and post-maintenance adjustment cycles.

This method can reasonably and accurately design nonlinear damping, improve nonlinear scaling and matching accuracy, save development cycle and cost, reduce training cycle, and facilitate the formation of a standard parameter scaling database of the model, which is convenient for reducing the same model. vibration design for reference.

Description of drawings

FIG. 1 is a schematic flowchart of a boundary element method for parameters of a commercial vehicle in an embodiment;

2 is a schematic diagram of a distribution diagram of sensors on a damper in an embodiment;

3 is a schematic diagram of a damping nonlinear characteristic curve in an embodiment;

Fig. 4 is the nonlinear damping segment scaling trend diagram in the embodiment;

FIG. 5 is a schematic diagram of parameter boundary element curve extraction in an embodiment.

In the figure, 1. Pressure sensor 2. Upper displacement sensor 3. Vibration-absorbing nonlinear damper 4. Lower displacement sensor 5. Non-linear damping overall characteristic amplification curve 6 Non-linear damping characteristic curve 7. Non-linear damping overall reduction characteristic curve 8 . Undamped characteristic reduction factor curve expressing function S (0n- _{i )} ·(1+ci ) 9. Undamping characteristic scaling factor curve expressing function S _{(0n-i) ·} (1-ci ) 10 . Variation interval 11. Optimal parameter boundary element.

Detailed ways

The content of the present invention will be further elaborated below in conjunction with the accompanying drawings and embodiments, but it is not intended to limit the present invention.

Example:

A boundary element analysis method based on the parameters of a commercial vehicle, comprising the following steps:

1) Apply a regularly changing load: Referring to Figure 2, first install a pressure sensor 1 on the upper port of the vibration-absorbing nonlinear damper 3 to collect the load changes, and at the same time set a pressure sensor 1 on the side wall of the vibration-absorbing nonlinear damper 3. The displacement sensor 2 and the lower displacement sensor 4 are used to detect the displacement change under the action of the load force. In the initial stage of the calibration design, a predetermined value of initial load N ₀ is applied to the upper and lower ports of the vibration-absorbing nonlinear damper 3, and the initial load N ₀ should be set so that the pressure sensor 1 on the vibration-absorbing nonlinear damper 3 senses a clear and obvious pressure, and then the load is gradually increased according to the load spacing F ₀ , and the sequentially increased load force can be expressed as: N ₀ , N ₀ +F ₀ , N ₀ +2F ₀ , N ₀ +3F ₀ , N ₀ +4F ₀ , N ₀ +5F ₀ ,…,N ₀ +nF ₀ , where the value of n is determined by the nonlinear vibration damping The limit stress value of the load that the damper 3 can carry is determined;

2) Obtain the damping characteristic curve: under the action of regular load stress, measure the sampling time t of the applied variable load acting on the vibration damping damper 3, and simultaneously measure the upper displacement sensor 2 and the upper displacement sensor on the side wall of the vibration damping damper 3. The displacement of the lower displacement sensor 4 changes after the load is applied. According to the calculation principle of the viscous damping theory, the size of the damping force F _R (t) is proportional to the speed, and the direction is opposite to the displacement speed. The displacement is assumed to be y(t) ,According to the corresponding relationship between damping force, displacement and time, preprocess the stress load signal collected from the pressure sensor 1 on the vibration-absorbing nonlinear damper 3 and the displacement signals collected by the upper displacement sensor 2 and the lower displacement sensor 4 , and further obtain the nonlinear damping characteristic curve 6 of the damping force changing with time, as shown in Figure 3, in order to observe the nonlinear change trend of damping, the traditional nonlinear damping curve is to obtain the overall nonlinear damping characteristic through the overall scaling method Amplification curve 5 and nonlinear damping overall reduction characteristic curve 7;

3) Piecewise weighting of damping characteristics: As shown in Figure 4, according to the nonlinear damping characteristic curve 6 obtained in step 2), for the weighted scaling factor, a piecewise discrete design of nonlinear damping is proposed. The stress on the pressure sensor 1 During the collection process of the load signal, the displacement signal collected by the upper displacement sensor 2 and the lower displacement sensor 4, it is assumed that in n different successive unit times, the piecewise weighted scaling factors of the nonlinear damping characteristic curve are: [c ₁ ,c ₂ ,c ₃ ,...,c _n ], then the original nonlinear weighted characteristic curve S ₀ is multiplied by different piecewise weighted scaling factors to obtain the characteristic curve segment [S ₁ , S ₂ , S ₃ ,...S _n-1 ,S _n ], in which, in order to ensure the continuity of the curve after scaling, the damping force data corresponding to the node position of each unit time does not participate in the scaling process, and the corresponding overall nonlinear The curve expression formula obtained after damping weighted scaling is formula (1):

According to the above discretization process, the original nonlinear damping characteristic curve is gradually discretized. In addition, in the value of the piecewise weighted scaling factor, the piecewise weighted scaling factors of the nonlinear damping characteristic curve are mutually exclusive. Interdependent, with arbitrary piecewise weighted scaling factors c _i and c _i+1 for illustration, after applying piecewise weighted scaling factor c _i , the corresponding scaling nonlinear damping characteristic segment is S _i , at this time If the non-damping characteristic amplification factor curve S _(0n-i) ·(1+c _i )8, the damping effect of the damper is better than that of the non-damping characteristic reduction factor curve S _{(0n-i) ·} (1-ci ) 9, the secondary segment scaling factor c _i+1 will tend to be corrected in the direction of enlargement, which can be expressed as:

c _i+1 = c _i +ξ _i

where ξ _i is the variation coefficient of the piecewise scaling factor, and the corresponding equivalent nonlinear damping characteristic curve of ci+1 can be expressed as:

S ₀ =S _0i+1 ·(1±ci ₊₁ )=S _0i ·(1± _{ci +ξ i )} ;

4) Establish a segmented weighted parameter set: Considering the interaction effect between adjacent segment scaling factors in step 3), separately collecting segment scaling factor and variation coefficient values on each segment can accurately quantify damping characteristics The curve feature is convenient to find the optimal scaling ratio of vibration attenuation under the load of a specific vibration damping mechanism. After collecting the segment scaling factor and variation coefficient value on each segment, the segment weighting parameter set is gradually established and can be expressed as:

S ₁ :S _(0,1) ,c ₁ ,0

S ₂ :S _(0,2) ,c ₂ ,ξ ₂

S ₃ :S _(0,3) ,c ₃ ,ξ ₃

...:...,...,...

S _n-1 :S _(0,n-1) ,c _n-1 ,ξ _n-1

S _n : S _{(0,n) ,} c _n ,ξn

Among them, S _(0,1) ,S _(0,2) ,S _(0,3) ,...,S _(0,n-1) ,S _(0,n) represent the original nonlinear damping characteristics segment, c ₁ , c ₂ , c ₃ ,...,c _n-1 ,c _n represent the piecewise scaling factor of the nonlinear damping characteristic curve, 0,ξ ₂ ,ξ ₃ ,...,ξ _n is Coefficient of variation value of each segment of nonlinear damping characteristic curve;

5) Extraction of parameter boundary elements: As shown in Figure 5, the original nonlinear damping characteristic curve 6 is multiplied by the respective piecewise scaling factor and coefficient of variation values, and the assumed variation interval 10 can be expressed as [S _0i ·(1 +c _i +ξ _i )S _0i ·(1- _ci +ξ _i )], then the obtained nonlinear piecewise weighted characteristic curve S ₀ will obtain an optimal parameter value (c _j and ξ _j ), this parameter value can make the damping effect of the shock absorber tend to be optimal in the scaling process of the i-th segment. Similarly, the optimal equal-segment scaling in each segment The parameter values such as factor and coefficient of variation are extracted one by one, and these extracted parameter values are outlined with a virtual curve, and the optimal parameter boundary element 11 of the overall nonlinear damping characteristic curve can be obtained. The overall vibration reduction optimization of the vibrator tends to be optimal, which is also the final design goal of the nonlinear characteristic curve;

6) The global boundary element design of the whole vehicle: After the establishment of the whole segmented weighted parameter set of a single vibration damping and the acquisition of the optimal parameter boundary element, since there are multiple vibration reduction and damping units distributed on the commercial vehicle, and each The load conditions are also different, so the design segment weighting parameters and optimal parameter boundary elements of each vibration damping are also different. Therefore, when designing the angle of the whole vehicle, each independent vibration damping needs to be multiplied by The penalty factor is used to cooperate with other vibration reduction and damping units to achieve the global optimal vibration reduction and damping distribution on the vehicle, which can be expressed as:

S _total =η ₁ ∑(S ₁ ,c ₁ ,ξ ₁ )+η ₂ ∑(S ₂ ,c ₂ ,ξ ₂ )+,...,η _n ∑(S _n ,c _n ,ξ _n )

Among them, η ₁ , η ₂ ,..., η _n are the distribution penalties of each nonlinear damping on the vehicle, S ₁ , S ₂ ,..., _Sn are nonlinear piecewise weighted characteristic curves, c ₁ ,c ₂ ,...,cn _is the piecewise scaling factor of the nonlinear damping characteristic curve, and the coefficient of variation of the piecewise scaling factor of ξ ₁ ,ξ ₂ ,..., _ξn .

Claims (1)

1. a method for boundary element analysis based on the parameters of commercial vehicles, is characterized in that, comprises the steps: 1) Apply a regularly changing load: first install a pressure sensor on the upper port of the vibration-absorbing nonlinear damper, and at the same time set an upper displacement sensor and a lower displacement sensor on the side wall of the vibration-absorbing nonlinear damper, at the initial stage of the calibration design. At this stage, a predetermined value of initial load N ₀ is applied to the upper and lower ports of the damping nonlinear damper, and the magnitude of the initial load should be set so that the pressure sensor on the damping nonlinear damper can sense a clear and obvious pressure, and then, according to The load spacing F ₀ increases the load step by step, and the increasing load force can be expressed as: N ₀ , N ₀ +F ₀ , N ₀ +2F ₀ , N ₀ +3F ₀ , N ₀ +4F ₀ , N ₀ +5F ₀ , ...,N ₀ +nF ₀ , where the value of n is determined by the limit stress value of the load that the vibration-absorbing nonlinear damper can carry; 2) Obtain the damping characteristic curve: under the action of regular load stress, measure the sampling time t of the applied variable load acting on the vibration damping damper, and simultaneously measure the upper displacement sensor and the lower displacement sensor on the side wall of the vibration damping damper The magnitude of the displacement changes after the load is applied. According to the calculation principle of the viscous damping theory, the magnitude of the damping force F _R (t) is proportional to the speed, and the direction is opposite to the speed of the displacement. Assuming that the displacement is y(t), according to the damping force The corresponding relationship between , displacement and time, the stress load signal collected from the pressure sensor on the vibration damping damper and the displacement signal collected by the upper displacement sensor and the lower displacement sensor are preprocessed, and the change of the vibration damping force with time is further obtained. The nonlinear damping characteristic curve of ; 3) Piecewise weighting of damping characteristics: According to the nonlinear damping characteristic curve obtained in step 2), for the weighted scaling factor, a piecewise discrete design of nonlinear damping is proposed. The stress load signal on the pressure sensor, the upper displacement sensor and the lower In the process of collecting displacement signals collected by the displacement sensor, it is assumed that in n different successive unit times, the size of the piecewise weighted scaling factors of the nonlinear damping characteristic curve are: [c ₁ ,c ₂ ,c ₃ ,... ,c _n ], then the original nonlinear weighted characteristic curve S ₀ is multiplied by different piecewise weighted scaling factors to obtain the characteristic curve segment [S ₁ , S ₂ , S ₃ ,...S _n-1 ,S _n ], wherein the damping force data corresponding to the node position of each unit time does not participate in the scaling process, and the corresponding curve expression formula obtained after weighted scaling of the overall nonlinear damping is formula (1):

According to the above discretization process, the original nonlinear damping characteristic curve is gradually discretized. In addition, in the value of the piecewise weighted scaling factor, the piecewise weighted scaling factors of the nonlinear damping characteristic curve are mutually exclusive. Interdependent, with arbitrary piecewise weighted scaling factors c _i and c _i+1 for illustration, after applying piecewise weighted scaling factor c _i , the corresponding scaling nonlinear damping characteristic segment is S _i , at this time If the non-damping characteristic amplification factor curve S _(0n-i) ·(1+c _i ) has a better damping effect on the damper than the non-damping characteristic reduction factor curve S _{(0n-i) ·} (1-ci ) , at this time, the secondary segment scaling factor c _i+1 will tend to be corrected in the direction of enlargement, which can be expressed as: c _i+1 = c _i +ξ _i where ξ _i is the coefficient of variation of the piecewise scaling factor, and the corresponding equivalent nonlinear damping characteristic curve of c _i+1 can be expressed as: S ₀ =S _0i+1 ·(1±ci ₊₁ )=S _0i ·(1± _{ci +ξ i )} ; 4) Establishing a segmented weighted parameter set: After collecting the segmented scaling factor and coefficient of variation values on each segment, the stepwise establishment of a segmented weighted parameter set can be expressed as: S ₁ :S _(0,1) ,c ₁ ,0 S ₂ :S _(0,2) ,c ₂ ,ξ ₂ S ₃ :S _(0,3) ,c ₃ ,ξ ₃ ...:...,...,... S _n-1 :S _(0,n-1) ,c _n-1 ,ξ _n-1 S _n : S _{(0,n) ,} c _n ,ξn Among them, S _(0,1) ,S _(0,2) ,S _(0,3) ,...,S _(0,n-1) ,S _(0,n) represent the original nonlinear damping characteristics segment, c ₁ , c ₂ , c ₃ ,...,c _n-1 ,c _n represent the piecewise scaling factor of the nonlinear damping characteristic curve, 0,ξ ₂ ,ξ ₃ ,...,ξ _n is Coefficient of variation value of each segment of nonlinear damping characteristic curve; 5) Extraction of parameter boundary elements: After multiplying the original nonlinear damping characteristic curve by the respective piecewise scaling factor and coefficient of variation value, the assumed variation interval can be expressed as [S _0i ·(1+c _i +ξ _i )S _0i ·(1-c _i +ξ _i )], then the obtained nonlinear piecewise weighted characteristic curve S ₀ will obtain an optimal parameter value (c _j and ξ _j ) in the corresponding variation interval. It can make the damping effect of the shock absorber tend to be optimal in the scaling process of the i-th segment. The virtual curve outlines these extracted parameter values, and the optimal parameter boundary element of the overall nonlinear damping characteristic curve can be obtained. is the final design goal of the nonlinear characteristic curve; 6) The global boundary element design of the whole vehicle: After completing the establishment of the whole segmented weighted parameter set of a single vibration damping and the acquisition of the optimal parameter boundary element, when designing the angle of the whole vehicle, each independent vibration damping needs to be separately designed. Multiply by the penalty factor to cooperate with other vibration reduction and damping units to achieve the global optimal vibration reduction and damping distribution on the vehicle, which can be expressed as: S _total =η ₁ ∑(S ₁ ,c ₁ ,ξ ₁ )+η ₂ ∑(S ₂ ,c ₂ ,ξ ₂ )+,...,η _n ∑(S _n ,c _n ,ξ _n ) Among them, η ₁ , η ₂ ,..., η _n are the distribution penalties of each nonlinear damping on the vehicle, S ₁ , S ₂ ,..., _Sn are nonlinear piecewise weighted characteristic curves, c ₁ ,c ₂ ,...,cn _is the piecewise scaling factor of the nonlinear damping characteristic curve, and the coefficient of variation of the piecewise scaling factor of ξ ₁ ,ξ ₂ ,..., _ξn .

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