自攻螺钉增强胶合木横纹承压性能试验

Compressive strength tests perpendicular to the grain of glulam reinforced with self-tapping screws

为研究自攻螺钉增强胶合木的局部表面横纹承压承载力,通过对22组共计110个胶合木试件的局部表面横纹承压承载力试验,系统研究承压位置、自攻螺钉长度、数量和布置形式等的影响,深入研究增强构件的破坏模式、承载力、变形性能和延性等。结果表明:自攻螺钉可以显著增强胶合木横纹承压性能,螺钉长度、数量和布置均为增强试件破坏模式和承载力的主要影响因素。当增强螺钉沿胶合木横纹承压方向通长设置时,由于其与横纹木材共同作用,因此增强效果更加明显,最终是自攻螺钉和横纹胶合木都会受压屈服。增强试件的横纹承压极限承载力和等效弹性模量最大可分别提高62.5%和46.8%,试件的位移延性系数可达1.66~2.95。

To investigate local compressive behavior perpendicular to the grain of glulam reinforced with self-tapping screws,a total of 110 specimens grouped in 22 were prepared to conduct the compressive load-carrying capacity experiments perpendicular to the grain.The influences of the positions,length,number and the arrangement of the self-tapping screws were investigated.The failure modes,load-carrying capacity,deformation behaviour and the ductility of the reinforced specimens were evaluated comprehensively.Results indicated that the compressive behavior increased obviously for the glulam specimens with self-tapping screws reinforcement.The length,number and the arrangement of the self-tapping screws had great influences on the failure modes and the load-carrying capacity.Specifically,when the length of the self-tapping screw was equal to that of glulam height,the improvement would be more obvious due to the good cooperative behaviors between glulam and screws.As a result,both glulam and screws would be yield finally.The maximum improvement of the ultimate compressive load-carrying capacity perpendicular to the grain and the equivalent elastic modulus of the reinforced specimens reached 62.5%and 46.8%,respectively.And the displacement ductility factor was between 1.66 and 2.95.