The authors have recently described the experimental in-plane shear tests of three composite slabs under monotonic loading to failure, focusing on the interaction between the slabs acting as diaphragms and the lateral load resisting system. The tests considered rib orientations both parallel and perpendicular to the supporting beam, as well as the end-anchorage details used in New Zealand and those used in Europe. A novel pure shear test rig was developed for this purpose. It was found that all specimens exhibited similar ultimate shear strength, and that the Eurocode overestimated the design strength for the European end-anchorage detail by almost a factor of two. An improved equation for the ultimate in-plane shear strength was proposed by the authors, modifying the Easterling and Porter equation to take into account the influence of the edge rebar, showing good agreement with the experimental test results.

In this paper, reversed cyclic in-plane shear tests of the same three slabs are now reported. Each test was repeated twice, resulting in six test results. The same novel pure shear test rig was adopted. In the elastic range, the reversed cyclic loading results were found to be similar to those of the monotonic tests, with the spine curve being very similar. The ultimate in-plane shear strength of all three was lower than that of the monotonic test by around 15%. Slippage of specimens was found to be insignificant in the elastic range.

作者最近描述了在单调加载至破坏下的三种复合板的面内剪切试验，重点研究了用作隔板的板与抗侧向载荷系统之间的相互作用。测试考虑了平行于支撑梁和垂直于支撑梁的肋骨方向，以及新西兰和欧洲使用的端部锚固细节。为此目的，开发了一种新型的纯剪切试验台。结果发现，所有试样均表现出相似的极限抗剪强度，而欧洲规范将欧洲端部锚固零件的设计强度高估了近两倍。作者提出了一个改进的极限面内剪切强度方程，

在本文中，现在报道了相同三个板的反向循环面内剪切试验。每个测试重复两次，得到六个测试结果。采用了相同的新型纯剪切试验台。在弹性范围内，反向循环载荷结果与单调试验的结果相似，而脊柱曲线非常相似。这三者的极限面内剪切强度均比单调试验低约15％。发现样品的滑移在弹性范围内微不足道。