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2D Seismic Panel Tests – with H & B invented Product & System – conducted by XI’AN University / China

Experimental research on seismic behavior of new-type cold-formed

thin-wall steel framing walls

LIU Bin1HAO Jiping1ZHONG Weihui1WANG Yingchun1HUANG Zhiguang1ZHAO Qiuli2
(1.Schoolof Civil Engineering, Xi’an University of Architecture and Technology, Xi’an 710055, China;

 

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Comparison of the results of this test and literature [5] [15]

In order to study seismic performance of this new type composite wall, the test results are analyzed and compared with the composite wall in with cladding board on both sides.

Literature[5][15] , see results in Table5. Composite wall, with cladding board on two sides, has relatively poor performance due to plate stitching and large amount ofself-tapping screws.

New type of composite wall, proposed in this paper, improves overall performance by using spraying materials instead of stitching cladding boards. It changes the intermittent screw connection of hanging boards at both sides composite wall to continuous connection between materials and steel frame. This enables that new type composite wall has much superior lateral performance than composite wall with cladding system.

From the results in the table,the unit yield load of the new type composite wall increases by 48.0%~96.6% and unit max load increases by 40.1%~106.0%, lateral stiffness increases by 89.9%~117.3% compared with the testing wall in literature [5],

Lateral stiffness increases by 13.5%~58.4% compared with the testing wall in literature [15].

Yield lateral displacement angle of new type composite wall is smaller than composite wall with cladding system, the maximum lateral displacement angle is almost equal with that in literature [5].

It indicates that new type wall has less deformation within elastic range and greater deformation capacity in elastic-plastic stage, which enables an excellent ductility.

It meets seismic requirement that ‘Buildings will not damage in small scale earthquake’ and ‘buildings will not collapse in large scale earthquake’.

 

 

Conclusion

In this paper,we conduct low frequency cyclic loading tests on one piece of cold-formed thin-wall steel framing wall and two pieces of new type cold-formed thin-wall steel framing composite walls, analyze the test results comprehensively, and make a comparison of the seismic performance between the new type composite wall and wall system with traditional cladding system,then we get the following conclusions:

(1)The failure mode of cold-formed thin-wall steel frame results from the failure of self-tapping screws at the joints of horizontal bracing and diagonal bracing as well as locally buckled flange of diagonal bracing. It is undesirable in the design, to ignore the enhancement from the interactions between cladding boards and steel skeleton since load bearing capacity and lateral stiffness of steel frame are relatively low.

(2)The new type cold-formed thin-wall steel framing composite walls proposed in this paper, has superior load bearing capability and lateral stiffness. It is a composite wall with ideal seismic resistance performance. The yield strength of this wall is19.52kN/m~20.57kN/m, and shear capacity is 22.35kN/m~25.25kN/m.

These data provide a reference for engineering design and application of this wall.

(3)This new type composite wall has greater lateral stiffness and smaller lateral displacement in elastic phase. In elastic-plastic phase, there is acertain amount relative sliding between the outer wall materials and lightweight steel frame, which help to avoid wall cracks and their enlargement.

(4)Compared with wall system with traditional cladding system, this new type composite wall has excellent thermal, acoustic, fire and impact resistance and hanging ability performance, improved the structure integrity with continuous spraying of thermal insulation materials, dramatically increased shear capacity and lateral stiffness as well as super ductility.

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