空心圆柱扭剪试验中广义应力路径的控制与实现

针对国内外动态空心圆柱扭剪仪(HCA)在设置广义应力路径时大都需要人为假设外荷载加载形式的现状,指出了这种假定对HCA仪模拟广义应力路径能力的局限。考虑到GCTS公司HCA-100能够独立地控制轴力、扭矩及内外围压独立地加载,通过缜密的数学推导,提出了由目标广义应力路径直接确定外荷载加载方式的计算公式,据此可以实现对任意形式的广义应力路径的模拟并通过试验验证了其可行性。在三维应力坐标系b-?-?中,探讨了典型广义应力路径的表示方法,以q恒定的主应力轴连续旋转的应力路径为例,讨论了内、外围压与广义应力路径之间的关系。简化并完善了HCA仪的控制过程,为后续试验研究提供了理论依据。

Control and realization of generalized stress paths in HCA test

Artificial assumptions are needed to set the generalized stress paths in hollow cylinder apparatus (HCA). The resulting limitations to imitate the generalized stress paths in HCA are analyzed. According to the function that GCTS HCA-100 can apply axial loads, torques, inner and outer pressures independently, the method that can determine the external loads directly by the target generalized stress path is put forward. In this way, the generalized stress paths of arbitrary form are presented by the exactly mathematical derivation, and the feasibility is verified by tests. The typical features of the generalized stress path tests are analyzed in 3-D coordinate system b-σ-τ. Based on the cyclic principal stress rotation stress path with constant q, the relationship between the inner and outer pressures and the generalized stress paths is discussed. The controlling process of HCA is simplified and improved, and it may provide a theoretical basis for future tests.