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许多系统或结构在动载荷作用下会表现出非线性滞回行为。通常情况下，人们往往认为滞回环是对称的。但是，在工程实际中还存在一些特殊的、不对称的滞回现象。例如，在对物料进行振动压实的过程中，由于压实机构的压下和回程中物料弹塑性变形规律不同，该振动压实系统存在不对称的滞回恢复力。本文提出用一种不对称模型描述这种不对称滞回性质，该不对称滞回模型由分段曲线组成。文章对这类系统在简谐激励下的响应特征进行了分析，得到一次近似解析解以及特有的直流分量和二次谐波等成分。然后又通过实验和数值模拟分别验证了模型的合理性。
Many systems or structures exhibit nonlinear hysteresis behavior under dynamic loads. Usually, people often think that the hysteresis loop is symmetrical. However, there are some special and unsymmetrical hysteresis in engineering practice. For example, during the process of vibrating and compacting the material, the vibrating and compacting system has an asymmetrical hysteresis recovery force due to the different elastic-plastic deformation rules of the material in the compacting mechanism and the return stroke. In this paper, an asymmetric model is proposed to describe the asymmetric hysteresis. The asymmetric hysteresis model is composed of piecewise curves. In this paper, the response characteristics of such systems under simple harmonic excitation are analyzed, and an approximate analytic solution as well as the unique direct current components and second harmonic components are obtained. Then we verify the rationality of the model through experiments and numerical simulations.