The torsion test was evaluated as a method for determining shear strength of full-size, structural lumber by length and depth studies. The statistical analysis did not show convincing evidence of a depth effect on shear strength, even after accounting for specific gravity and shear span as covariates. Failure modes were similar to shear failures observed in bending tests, and involved a longitudinal shear crack at the wide face, which propagated toward the ends of the specimens and through the cross section perpendicular to growth rings. Based on results of this study, the torsion test is the best practical method for determining pure shear strength of full-size, structural lumber.
參考答案:扭转试验是一种全面检测剪切机力量的方法，研究建筑用板材长度和厚度的途径．研究数据并没有展示确切的关于厚度对剪切机力量影响的证据，即使考虑了特定的中立和剪切机的跨度之类的变量．模式的错误就如同剪切机在弯曲测试中出现的错误一样，这涉及到在宽敞表面上纵向剪切机的破裂，这就展示了样品的最终状态以及通过交叉部分垂直地制造出环壮物．基于这一研究，扭转实验是最佳的具有可操作性的方法，用来全面检测剪切机力量和建筑用板材
shear当名词就是剪切机．不知道对不对 反正自己又操练了一把 嘿嘿
