木质工字梁腹板端头压板稳定性初探

End Instability of the Web of Wooden I-Joist under Perpendicular Loading

对木质工字梁(IJ)腹板端头压板失稳行为的试验结果表明:木大片刨花板(WWB)、竹大片刨花板(BWB)和胶合板(W-Ply)腹板的失稳均为极值点失稳,且都经历了弹性、弹塑性和屈曲阶段的变形;大片刨花类腹板的失稳破坏特征是层间剪切破坏,胶合板腹板的失稳破坏特征是表板折断破坏;失稳临界荷载的强弱顺序为:W-ply>BWB>WWB;失稳破坏荷载的大小顺序为:(W-Ply≈BWB)>WWB;失稳后残余承载能力的强弱顺序为:BWB>W-Ply>

The tests of end instability of the web of wooden I-Joist under perpendicular loading were carried out with 3 kinds of material, waferboard （ WWB）, bamboo waferboard （ BWB ） and wood-plywood （W-Ply） being used as webs. Experiment results showed： all the webs made of different kinds of material had limiting maximum instability loading, and their deformation went through elastic, elasto-plastic and buckling stages successively; the main form of end instability of webs made of WWB or BWB was shearing rupture among the wafers, while that of W- Ply web was tensile fracture of surface veneer; the order of limiting instability load- ing, the order of end instability rupture loading and that of remanent load bearing capacity were W- Ply 〉 BWB 〉 WWB, （W-Ply ≈ BWB） 〉 WWB, and BWB 〉 W-Ply 〉 WWB, respectively.