不同标准下胶合木胶层压缩剪切强度测试方法比较

Comparison of different standard test methods for compressive shear strength of bondline in glulam

分析比较了中国国标GB/T 17517—1998、欧洲标准EN392以及美国标准ASTM D905等3种相关标准下胶合木胶层压缩剪切强度测定结果的异同。结果表明:根据现有标准测得的胶层剪切应力并非真实剪切应力,而是剪切应力与胶层正应力的合力。当正应力表现为拉力时,试验所测剪切强度值低于真实值。为避免正应力的存在,提出了一种非标准的测试方法,以提高胶层压缩剪切强度测试精度。

The compressive shear strength of bondline in the glulam was tested and compared according to Chinese standard GB / T 17517—1998,European standard EN392 and American standard ASTM D905. The results showed that the tested shear stress was not the true shear stress in the bondline,but a combination of shear stress and normal stress. The tested values were lower than the true shear strength when the normal stress was tensile stress perpendicular to the bondline. To avoid the existence of the normal stress,a novel and non-standard test method was proposed aiming to improve the accuracy of bondline shear strength test.