NZ501392A - Diaphragm with perimeter edging on structural panels which resists lateral forces - Google Patents

Abstract

Provided is a horizontal, vertical or angularly disposed diaphragms which will resist lateral forces imposed upon a building structure and comprises a shear resisting element being one or more structural panels, a frame and a fastening system for connecting the frame to the shear resisting element. The diaphragm particularly comprises a structural panel having a distal side, a proximal side and a plurality of edge faces; a first framing member disposed in registration with the proximal side of the structural panel near one of the edge faces and a second framing member disposed in registration with the proximal side of the structural panel near a different one of the edge faces of the structural panel; a plurality of perimeter fasteners connecting the structural panel to each of the framing members; and a means for reducing bending of the perimeter fasteners attached to a substantial number of the perimeter fasteners, the means for reducing bending of the perimeter fasteners acting when the lateral forces are imposed on the building structure, where the structural panel is connected by the perimeter fasteners to only the first and second framing members. Addition to 501392

Description

'jO 1392 FORM 5 NEW ZEALAND S.9 Reg.19(4) Fee: $250.00 ^01392 Insert number of Provisional Specification(s) (if any) and date(s) of filing; otherwise leave blank COMPLETE SPECIFICATION Insert Title of Invention DIAPHRAGM WITH PERIMETER EDGING ON STRUCTURAL PANELS PATENTS ACT 1953 Number: Date: Insert full name, full street address and nationality of (each) applicant l/WE SIMPSON STRONG-TIE COMPANY, INC., a corporation organised and existing under the laws of the State of California, United States of America, of 4637 Chabot Drive, Suite 200, Pleasanton, California 94588, United States of America hereby declare the invention for which l/we pray that a patent may be granted to me/us and the method by which it is to be performed, to be particularly described in and by the following statement:- Indicate if following page is numbered "1a" .9.96 The following page is numbered "1a" - 1 UltUECTUAL PHUPERTY OFFICE] ' , OF N.Z. 1 26 NOV 1999 .ftECEIVFn This invention relates to a modification of the invention described and claimed in New Zealand Patent Specification No. 330178.

This invention relates to horizontal, vertical or angularly disposed diaphragms which resist structural forces. As herein used, a diaphragm is a large, thin structural element that is loaded in its plane. A diaphragm at its most basic level has three components: a shear resisting element, which consists of one or more structural panels, a frame and a fastening system for connecting the frame to the shear resisting element. The structural panels which make up the shear resisting element are commonly made of 4'x 8' plywood or Oriented Strand Board (OSB) sheets. Vertical diaphragms in a structure are commonly called shearwalls. Specifically, this invention relates to an improved method of constructing diaphragms. The present invention improves on standard construction and fabrication methods to reduce the bending of the fasteners that make the mechanical connection between the structural panels and the perimeter framing members that support the structural panels.

All structures must be designed to resist lateral forces. Structural units designed to resist lateral forces are commonly called lateral force resisting systems. Lateral forces on a building are typically produced by wind loading and seismic forces. Both, but especially seismic forces, cause cyclic loading, that is, the force on the building reverses direction. The extensive damage caused to buildings by the January 1994 earthquake at Northridge, California has demonstrated that lateral force resisting systems must be improved to better resist cyclic (reversed) lateral loading.

I i fc'.'.rCV'J P^O| Or,at; d; t 9 MAS 2331 In general there are three types of lateral force resisting systems used in framed buildings. The first type, rigid frames, resist lateral forces by bending in the frame members. The second type, trusses or braced frames, resist lateral forces by primarily carrying the resulting tension and compression forces in diagonal members or cross braces. The third type, shearwalls or diaphragms, are large, flat structural units that act like deep, thin beams with the structural panel or panels of the diaphragms acting as the "web" of the beam and the chords of the diaphragms acting like the "flanges" of the beam. It is thought that shear deformation is the significant action in diaphragms.

The present invention provides an improved method of constructing shearwalls and horizontal diaphragms to serve as improved lateral force resisting systems.

When considered in its function of resisting lateral forces, a typical shearwall or diaphragm consists of three structural elements: a frame, a shear resisting element, and a fastening system for attaching the shear resisting element to the frame.

The diaphragm, in turn, is integrated into the structure via a connection system. The connection system must be designed to transfer the lateral forces imposed on the building into the diaphragm. In the case of shearwalls or vertical diaphragms, special anchors or transfer members for resisting the moment forces imposed on the shearwall may also be required.

In a shearwall, these special anchors typically consist of anchor bolts and holdowns, connecting the bottom of the chords to a structural member below the shearwall. These anchors resist tension forces acting to overturn the shearwall. A holdown is typically attached to the inner face of each chord with heavy screws, nails or bolts. The holdown receives a bolt which is connected to an anchoring structural member below.

Diaphragms and shearwalls are connected to the other structures of the building in a variety of ways so that lateral forces imposed on the building will be transferred to them. For example, it is common to attach a first story shearwall to the foundation on which it sits with foundation anchor bolts. The anchor bolts are embedded in the foundation and run through the bottom strut or mudsill of the shearwall and attach with a washer and nut.

When viewed in terms of resisting lateral forces, the frame is primarily an intermediate member, transmitting the lateral forces imposed on the building to the shear resisting element. It does this through the fastening system. In most diaphragms, the structural panels are attached to the frame with mechanical fasteners such as nails, screws or staples, spaced around the perimeter of the structural panels according to prescribed schedules. As used in this application, these fasteners located at the perimeter of the structural panel will be called perimeter fasteners to distinguish them from other fasteners located farther in from the edge faces of the structural panels. It should be noted that perimeter fasteners refer to the nails at the perimeter of the structural panels and not just the perimeter of the shear resisting element which can comprise a plurality of structural panels.

Nails commonly serve as the perimeter fasteners when wooden framing members are used. The perimeter fasteners are driven into the distal face of the structural panel at its perimeter, through the structural panel, and into the framing members. Through testing, the inventors have found that with improvements in the other elements of the typical shearwall, the perimeter fasteners have become the critical weak link through which failure of the overall system occurs.

The shear resisting element, as its name implies, works primarily in shear. The shear resisting element can be a single structural panel, if the diaphragm is small, or a number of structural panels, if the diaphragm is large. Typically structural panels for use in diaphragms are made of plywood or Oriented Strand Board (OSB) of structural grades, because they give a diaphragm high shear resisting values as well as having other desirable characteristics. Plywood and OSB come in many different grades. Typically, structural grades such as 15/32" APA Structural 1 Rated Sheeting 32/16, Exposure 1 are used in diaphragms to obtain sufficiently high shear values. Other types of structural panels include: fiberboard, waferboard, particle board, gypsum wall board and high density particle board. Structural panels made from composites of different materials are also known in the art. U.S. Patent No. 4,016,697, granted to Ericson on April 12, 1977 teaches completely cladding one side of gypsum wall board with a thin sheet of steel to improve its structural characteristics. Kevlar is also beginning to be used with engineered wood products as ply materials.

The most basic frame consists of chords and struts located at the perimeter of the diaphragm. In a shearwall, the top strut is commonly called the top plate and the bottom strut is commonly called the bottom plate or mudsill. The chords are commonly called end studs. The framing members can be made of wood, engineered wood products, such as glulam, or steel, to name a few common materials.

Most diaphragms will be made with a variety of layouts of the framing members. If a diaphragm consists of more than one structural panel, framing members need to be placed at the joint or joints of the structural panels to tie them together, and provide support to the structural panels. If the diaphragm serves as a load bearing structural element as well as a lateral force resisting element, intermediate members will often be added to strengthen the diaphragm against particular forces.

A shearwall, for example, is typically designed to serve as a load bearing unit for the structures above it, as well as a lateral force resisting element. Both forces work in the plane of the shearwall. In a wood frame building, the walls are built with intermediate studs that connect the top plate to the bottom plate to give the wall sufficient load bearing capacity. Ordinarily, these intermediate studs are spaced 16 inches on center from each other and from the end chords to give the shear wall sufficient strength. For example, in an 8' x 8' shear wall, comprising two 4' x 8' structural panels disposed vertically, intermediate studs spaced 16" on center will occur both at the vertical joint of the 4' x 8' structural panels and at intermediate points along each of the structural panels. The intermediate stud at the joint between the structural panels acts as a framing member to connect the structural panels to form a single shear resisting element. It also provides bearing support for the top plate. The other intermediate studs provide bearing support to the top plate. These other intermediate studs are also attached to the structural panels.

Sometimes, blocking members will be added to shear walls. Blocking members are relatively short lengths of board placed normal to and between the intermediate studs. If the shear wall is made with a horizontal joint between the structural panels, blocking will be added at the joint to connect the structural panels along the entire length of the joint. For shearwall action all edges of the structural panels must be supported. The blocking also provides support to the studs against buckling under compression loads transmitted through the top plate.

Horizontal diaphragms are also designed to serve as load bearing units, as well as a lateral force resisting systems. Horizontal diaphragms in wood frame construction serve as roofs and floor systems. Horizontal diaphragms, in their load bearing capacity, are loaded normal to their plane. As roof and floor systems, they are generally rather large; thus these diaphragms typically comprise a number of structural panels. These structural panels need to be connected at all their joints as well as the outer edges of the diaphragm. The structural panels also need to be supported at intermediate points to prevent excessive deflection under loading normal to the diaphragm. In a roof or floor, the framing members are given various names such as: stiffeners, rafters, joists, % purlins, subpurlins, beams, headers, and girders. Blocking may also be provided.

As mentioned above, the inventors tested shearwalls made according to current building practices with the best commercially available components under cyclic loading conditions. They discovered that the predominant failure mode is the flexing and fatiguing of the nails around the perimeter or outer edges of the structural panels that connect the structural panels to the frame of the diaphragm. The present invention addresses this problem, allowing shearwalls and diaphragms to be both stronger and stiffer.

It is an object of the present invention to create a diaphragm that is highly resistant to failure under cyclic loading by lateral forces.

It is a further object of this invention to improve the mechanical connection between the structural panel and framing members of a diaphragm, so that the fasteners that make the mechanical connection can better withstand cyclic or reversing lateral forces by bending less under such forces.

* ;FIG. 1 is a perspective view of a vertical diaphragm or shearwall built according to the preserlt invention. ;FIG. 2 is a perspective view of a portion of a unitary perimeter edging member, formed as a substantially u-shaped member. ;PIG. 3 is cross section of a portion of a shearwall built according to the present invention taken along line 3 — 3 of ;1 7< ® 9 ' ;X.J <y>J ;^ FIG. 1, showing one of the substantially u-shaped perimeter edging members with both of its flanges pierced by a perimeter fastener that connects the structural panel to a framing member. ;The present irwanticn reJrttes to a diaphragm fiat: resisting lateral forces iitpceed cn a building structure, an improved mechanical connection comprising: ;a- a structural panel having a distal side, a proximal • side and a plurality of edge faces; ;b. a first framing member disposed in registration with said proximal Bide of said structural panel near one of said edge faces and a Becond framing member disposed in registration with said proximal side of said structural panel near a different one of aaid edge faces of said structural panelj c. a plurality of perimeter fasteners connecting said structural panel to each of said framing members; ;d. means for reducing bending of said perimeter fasteners attached to a substantial number of eaid perimeter fasteners, said means for reducing bending of said perimeter faateners acting when said lateral forces are imposed on said building Btructure, wherein said structural panel is connected by said perimeter fasteners to only said first and second framing members. ;In a further aspect the present invention relates to a diaphragm for resisting lateral forces imposed on a building structure, an improved mechanical connection comprising! ;a. a structural panel having a distal eide, a proximal side and a plurality of edge faces» ;b. a first framing member disposed in registration with said proximal eide of said structural panel near one of said edge faces and a second framing member disposed in registration with Baid proximal side of said structural panel near a different one of said edge faces of said ;• - structural panel; ;fE'' cCi"'j - ' ;oiF'CH o,: . . & plurality of perimeter fasteners connecting said ;<1 in wj 'n ,1 I structural panel to each of said framing members; ;(i » iL w ^ 8 i - ;a. means for reducing bending of eaid perimeter HI J, fJ). ,"' , ) ! fasteners attached to at least one of said perimeter —— =. fftutener-B, aaid mesne foif reducing bending of said ;perimeter fasteners acting when said lateral forces are imposed on said building structure, wherein said structural panel is connected by said perimeter fasteners to only said first and second framing members. ;In a further aspect the present invention relates to a diaphragm for resisting lateral forces imposed on a building structure, an improved mechanical connection comprising; ;a. a structural panel having a distal eide, a proximal side and a plurality of edge faces; ;b. a first framing member disposed in registration with said proximal side of said structural panel near one of said edge faces and a second framing member disposed in registration with said proximal side of said structural panel near a different one of said edge faces of said structural panel, Baid framing members each having two ends; ;c. a plurality of perimeter fasteners connecting said structural panel to each of said framing members/ ;d. means for reducing bending of said perimeter fasteners attached to a plurality of said perimeter fasteners located near one of said ends of one of eaid framing members., said means for reducing bending of said perimeter fasteners acting when said lateral forces are imposed on said building structure , wherein said structural panel is connected by said perimeter fasteners to only said first and second framing members. ;In a further aspect the present invention relates to a diaphragm for resisting lateral forces imposed on a building structure, an improved mechanical connection comprising: ;a. one or more structural panels, each having a distal side, a proximal side and a plurality of edge faces; ;b. a first elongated framing member disposed in registration with said proximal sides of said one or more o a.::. structural panels near one of said edge faces of each of ^ 2"*-;<j jsaid one or more structural panels and one or more second (elongated framing members disposed in registration with n v " r ~ " > j J < said proximal sides of said one or more structural panels near a different one of said edge faces of each of said one or more etrucUural. paneln? fr^ ^ Z1 cv ^ ^ _ 10 ^ li ^ c. 0 plurality of perimeter fasteners connecting said one or more structural panels to each of said framing members along substantially the entire length of eaid framing members, said perimeter fasteners being spaced approximately 2U apart in a direction generally parallel to eaid edge faces of said one or more structural panels to which said framing members are connected; d. meanB for reducing bending of said perimeter faBteners attached to at least one of Baid perimeter fasteners, said means for reducing bending of said perimeter fasteners acting when said lateral forces are imposed on said building structure,, wherein each structural panel is connected by perimeter fasteners to only two framing members.

In a further aspect the present invention relates to a diaphragm for resisting lateral forces imposed on a building structure, an improved mechanical connection comprising: a. one or more structural panels, each having a distal side, a proximal side and a plurality of edge faces,- b. a first elongated framing member disposed in registration with said proximal sides of said one or more structural panels near one of said edge faces of each of said one or more structural panels and one or more second elongated framing members disposed in registration with said proximal sides of said one or more structural panels near a different one of said edge faces of each of said one or more structural panels; c. a plurality of perimeter fasteners connecting said one or more structural panels to each of said framing members along substantially the entire length of said framing members, said perimeter fasteners being spaced approximately 1.0" to 4" apart in a direction generally parallel to said edge face of said one or more structural 1 panels to which said framing members are connected; d. means for reducing bending of said perimeter fasteners attached to at least one of said perimeter Irastenero, said means for reducing bending of said imposed on said building structure, wherein each structural panel is connected by perimeter fasteners to only two framing members.

In a further aspect the present invention relates to a diaphragm for resisting lateral forces imposed on a building structure, an improved mechanical connection comprising: a, a structural panel having a distal eide, a proximal eide and a plurality of edge faces; b. a framing member disposed in registration with aaid proximal side of said structural panel near one of eaid edge faces and a second framing member disposed in registration with said proximal eide of said structural panel near one of said edge faces of said structural panel, said framing members, each having two ends; e. a plurality of perimeter fasteners connecting said structural panel to each of said framing members; d. means for reducing bending of said perimeter fasteners attached to a plurality of said perimeter fasteners located near one of eaid ends of one of aaid framing members, aaid means for reducing bending of eaid perimeter fasteners not extending beyond said diaphragm, and eaid means for reducing bending of said perimeter fasteners acting when said lateral forces are imposed on said building structure, wherein said structural panel is connected by said perimeter fasteners to only said first and second framing members.

Diaphragms can take a variety of shapes. For example, FIG. 1 shows a vertical diaphragm or shearwall 9, composed of only one structural panel 1, set on a foundation 10. The frame 6 of the shearwall 9 consists of framing members 2 disposed near the edge faces 5 of the structural panel 1 and intermediate framing members 11. Means for reducing bending of the perimeter fasteners are disposed at the perimeter of the structural panel 1. Foundation bolts 12 attach the frame 6 to the foundation 10. A holdown 13 is shown attached to the frame 6. An anchor bolt 14 is shown in FIG. 1 which attaches the holdown 13 to the foundation 10.

The means for reducing bending of the perimeter fasteners can be formed as a single perimeter edging member 18 that is pierced by substantially all of the perimeter fasteners 7.

See FIG. 2. The single perimeter edging member 18 is formed as continuous member disposed only near the edge faces 5 of the structural panel 1 so as to be pierced by the perimeter fasteners 7.

As shown in FIGS. 1 and 3, in the preferred embodiment, the perimeter edging members are formed as elongated, substantially u-shaped perimeter edging members 21, having central members 25 that have first and second flanges 26 and 27 extending from the central members 25. Both of the flanges 26 and 27 are pierced by each perimeter fastener 7 receiving the benefit of the means for reducing bending of the perimeter fasteners.

The first and second flanges 26 and 27 of the substantially u-shaped perimeter edging members can be disposed in relation to the structural panel 1 in a variety of ways, depending on the builder's preferences.

The first flanges 26 of the substantially u-shaped perimeter edging members 21 can be disposed between the framing members 2 and the proximal side 4 of the structural panel 1, while the second flanges 27 are disposed on the distal side 3 of the structural panel 1 near the edge faces 5.

Alternatively, the first flanges 26 of the substantially u-shaped perimeter edging members 21 can be disposed within the structural panel 1 near the edge faces 5, and the second flanges 27 of the u-shaped perimeter edging members 21 can be disposed on the distal side 3 of the structural panel 1 near the edge faces 5.

The first flanges 26 of the substantially u-shaped perimeter edging members 21 can also be disposed between the framing members 2 and the proximal side 4 of the structural panel 1, and the second flanges 27 can be disposed within the structural panel 1.

Further, the first flanges 26 of the substantially u-shaped perimeter edging members 21 can be disposed within the structural panel 1 near the edge faces 5, and the second flanges 2 7 can also be disposed within the structural panel 1 near the edge faces 5.

In the preferred embodiment, the means for reducing bending of perimeter fasteners is formed by one or more substantially u-shaped perimeter edging members 21, pierced by a plurality of perimeter fasteners 7. Substantially u-shaped perimeter edging members 21 reduce nail bending well while being easier to install than the other embodiments. By being easier to install, the preferred embodiment better ensures that all diaphragms constructed with means for reducing bending of the perimeter fasteners are uniform in the shear resisting load values they achieve.

The dimensions of the preferred substantially u-shaped perimeter edging members 21 depend on the dimensions of the structural panel 1. When used with a 15/32" thick structural panel l, the preferred embodiment is formed with 1/2" central members 25 and 1" first and second flanges 26 and 27 extending from the central members 25.

The means for reducing bending of the perimeter fasteners can be made of any material that has a higher bearing strength than the structural panel 1 with which it is used. When the structural panels 1 are plywood or OSB, materials such as aluminum, steel and certain plastics could be used. In the preferred embodiment, where the structural panel is OSB, the means for reducing bending of the perimeter fasteners is formed from 20 gauge galvanized sheet metal.

The means for reducing bending of the perimeter fasteners can be bonded, mechanically attached, incorporated into the structural panels 1 or attached during assembly of the diaphragm. The preferred method is to attach the means for reducing bending of the perimeter fasteners during assembly to accommodate diaphragms of all shapes and sizes. If the diaphragm is large and will be built with a number of structural panels 1 of equal size, it may be preferable to incorporate the means for reducing bending of the perimeter fasteners into the structural panels 1 as they are created. For example, a kerf cut could be made that runs the length of each of the edge faces 5 of the structural panel 1, and then the first flanges 26 of the substantially u-shaped perimeter edging members 21 could be inserted into the kerf cuts, achieving a friction fit.

Openings can be formed in the means for reducing bending of the perimeter fasteners to facilitate hand installation of the perimeter fasteners 7; however, the preferred method is to, at least initially, drive the perimeter fastener 7 with a power tool, in which case no openings are necessary.

The perimeter edging members are preferably made in 4' lengths. Structural panels 1 are typically sold as 41 x 8' panels, and a 4' long perimeter edging member integrates easily with these dimensions and is also easy to handle. See FIG. 1.

The preferred perimeter fasteners 7 for attaching the structural panel 1 to the framing members 2 are lOd x 3" long common nails. In a shearwall 9 with wood framing members 2, the perimeter fasteners 7 should be spaced around the perimeter of the structural panel 1 at 2" on center to provide the highest shear value for the shearwall 9. Less closely spaced perimeter fasteners 7 provide lower shear resistance values for the diaphragm, while more closely spaced perimeter fasteners 7 can lead to splitting of the framing members 2 when wooden framing members 2 are used. Perimeter fasteners 7 should be spaced at least 3/8 inches from the edge faces 5 of the structural panel 1.

The structural panels 1 are preferably made from Oriented Strand Board 15/32" APA Structural 1 Rated Sheeting 32/16, Exposure 1. Higher diaphragm shears can be carried with increased structural panel 1 thickness, however, increased thickness adds cost to the materials. Structural panels 1 with the above specifications are generally sufficiently strong without being too costly.

In a 41 wide by 81 tall shearwall 9 constructed from a single 4' x 8' structural panel 1 disposed vertically, with wooden framing members 2, and resting on a foundation 10, the chords or framing members disposed at the vertical edge faces of the structural panel 1 are preferably made of kiln-dried Southern Yellow Pine (MSR) 4x4s. The bottom strut that rests on the foundation 10 should be a pressure treated 2x4. The top strut or the framing member near the top edge of the structural panel 1 is preferably formed as two kiln-dried Southern Yellow Pine (MSR) 2x4s joined together.

Claims (1)

1. - 17 - * i n;• 3 y ii ^ ^;WHAT I/WE CLAIM IS:;1. In a diaphragm for resisting lateral forces imposed on a building structure, an improved mechanical connection comprisingi a. a structural panel having a distal eide, a proximal ' eide and a plurality of edge faces;;b. a first framing member disposed in registration with said proximal side of said structural panel near one of said edge faces and a second framing member disposed in registration with said proximal side of said structural panel near a different one of said edge faces of said structural panel/;c. a plurality of perimeter fasteners connecting said structural panel to each of said framing members;;d. meanB for reducing bending of said perimeter fasteners attached to a substantial number of said perimeter fasteners, said means for reducing bending of said perimeter faatenere acting when said lateral forces are imposed on said building structure , wherein said structural panel is connected by said perimeter fasteners to only said first and second framing members.;2. In a diaphragm for resisting lateral forces imposed on a building structure, an improved mechanical connection comprising};a. a structural panel having a distal side, a proximal side and a plurality of edge facesj b. a first framing member disposed in registration with said proximal eide of said structural panel near one of said edge faces and a second framing member disposed in registration with said proximal side of said structural panel near a different one of said edge faces of said structural panelj c. a plurality of perimeter fasteners connecting said structural panel to each of said framing • members;;d. means for reducing bending of said perimeter fasteners attached to at least one of said perimeter fastenem, eaid means for reducing bending of said;perimeter fasteners acting when said lateral forces are imposed on said building structure, wherein said structural panel is connected by said perimeter fasteners to only said first and second framing members.;3, In a diaphragm for resisting lateral forces imposed on a building structure, an improved mechanical connection comprising;;a. a structural panel having a distal side, a proximal side and a plurality of edge faces;;b. a first framing member disposed in registration with said proximal Bide of said structural panel near one of said edge faces and a second framing member disposed in registration with said proximal side of said structural panel near a different one of said edge faces of eaid structural panel, eaid framing members each having two enda;;c. a plurality of perimeter fasteners connecting aaid structural panel to each of said framing members;;d. means for reducing bending of said perimeter fasteners attached to a plurality of said perimeter faatenere located near one of said ends of one of eaid framing member.fi, said means for reducing bending of said perimeter fasteners acting when said lateral forces are imposed on said building structure., wherein said structural panel is connected by said perimeter fasteners to only said first and second framing members.;4. In a diaphragm for resisting lateral forces imposed on a building structure, an improved mechanical connection comprising;;a. one or more structural panels, each having a distal Bide, a proximal side and a plurality of edge faces;;b. a first elongated framing member disposed in registration with said proximal sides of said one or more structural panels near one of said edge faces of each of said one or more structural panelo and one or more second, elongated framing members disponed in registration with aaid proximal sides of aaid one or more structural panels near a different one of oaid edge faaes of each of said one oar moire structural paneln;;- 19 -;c. a plurality of perimeter fasteners connecting said one or more structural panels to each of said framing members along substantially the entire length of eaid framing merobare, said perimeter fasteners being spaced approximately 2U apart in a direction generally parallel to eaid edge faces of eaid one or more structural panels to which said framing members are connected;;d. means for reducing bending of said perimeter fasteners attached to at least one of said perimeter faatenere, said means for reducing bending of said perimeter fasteners acting when Baid lateral forces are imposed on said building structure, wherein each structural panel is connected by perimeter fasteners to only two framing members.;5. In a diaphragm for resisting lateral forces imposed on a building structure, an improved mechanical connection comprising:;a. one or more structural panels, each having a distal eide, a proximal side and a plurality of edge faces;;b. a first elongated framing meitfoer disposed in registration with said proximal Bides of aaid one or more structural panels near one of said edge faces of each of said one or more structural panels and one or more second elongated framing members disposed in registration with said proximal sides of said one or more structural panels near a different one of said edge faces of each of said one or more structural panels;;c. a plurality of perimeter fasteners connecting eaid one or more structural panels to each of said framing members along substantially the entire length of said framing members, said perimeter fasteners being spaced approximately 1.0* to 4" apart in a direction generally parallel to said edge face of said one or more structural panels to which paid framing metribera are connected; d. means for reducing bending of said perimeter fasteners attached to at least one of said perimeter fasteners, said means for reducing bending of said r perimeter fasteners acting when said lateral forces are imposed on said building structure, wherein each structural panel is connected by perimeter fasteners to only two framing members. 6. In a diaphragm for resisting lateral forceB imposed on a building structure, an improved mechanical connection comprising: a. a structural panel having a distal side, a proximal side and a plurality of edge faces; b. a framing member disposed in registration with Baid proximal side of said structural panel near one of eaid edge faces and a second framing member disposed in registration with said proximal eide of eaid structural panel near one of said edge faces of said structural panel, said framing members, each having two ends; c. a plurality of perimeter faBteners connecting said structural panel to each of Baid framing members; d. means for reducing bending of said perimeter fasteners attached to a plurality of said perimeter faBteners located near one of eaid ends of one of aaid framing members, said means for reducing bending of oaid perimeter fasteners not extending beyond eaid diaphragm, and said means for reducing bending of said perimeter fasteners acting when said lateral forces are imposed on said building structure, wherein said structural panel is connected by said perimeter fasteners to only said first and second framing members. 7. The connection of claims 1, 2, 3, 4, 5, or 6 wherein: said perimeter fasteners are nails. 0. The connection of claims 1, 2, 3 4, 5, or 6 wherein: said perimeter fasteners do not patJO the way through said framing members. 9. The connection of claims 1, 2, 3 4, 5, or 6 wherein: said structural panel is made from wood. 10. The connection of claims 1, 2, 3 4, S, or 6 wherein: - 21 - said structural panel is supported near all of said edge faces. 11. The connection of claims 2, 4, or 5 wherein: a. said means for reducing bending of said perimeter fasteners are attached to a plurality of said perimeter fasteners attached to said first framing member; and b. Baid means for reducing bending of said perimeter fasteners are attached to a plurality of said perimeter fasteners attached to said second framing member. 12. The connection of claims 1, 2, 3, 4, 5, or 6 wherein; said means for reducing bending of said perimeter fasteners is made from light gauge, sheet metal. 13. The connection of claims 1, 2, 3, 4, 5, or 6 wherein: a. said means for reducing bending of said perimeter fasteners are attached to a plurality of eaid perimeter fasteners attached to said first framing member; b. said means for reducing bending of said perimeter fasteners are attached to a plurality of said perimeter fasteners attached to said second framing member; and c. said means for reducing bending of said perimeter fasteners have portions disposed on said distal side of said structural panel. 14. The connection of claim 13 whereini said perimeter fasteners do not pass all the way through said framing members. 15. The connection of claims 1, 2, 3, 4, 5, or 6 wherein: a. said means for reducing bending of said perimeter fasteners are attached to a plurality of said perimeter fasteners attached to Baid first framing member; b. said means for reducing bending of said perimeter fasteners are attached to a plurality of said perimeter fasteners attached to said second framing member; and 501J 22 1 c. eaid means for reducing bending of said perimeter fasteners do not extend beyond said framing members. 16. The connection of claim 15 wherein: said perimeter fasteners do not pass all the way through said framing members. 17. The connection of claims 13, 14, 15, or 16 wherein: said structural panel is made from wood. J. D. HARDIE & CO. Patent Attorneys for the Applicarit(s). 2SN0V 1333 I