关键词: 本构方程, 波纹板结构, 数值模拟, 形状记忆合金

Abstract: As a kind of functional material, NiTi shape memory alloy (SMA) has the advantages of great output recovery force and stable performance. So it can be used as driving component of initiatively deforming structure. The corrugated sheets structure driven by SMA is made by connecting SMA strips with corrugated sheets in the form of discrete dots. The purpose of controlling structure deform initiatively can be achieved by electrifying SMA and utilizing its drawing or retractile force. Simultaneously, in order to forecast the deformation response of the structure, numerical simulation is carried out by using finite element software ANSYS. In the existing universal finite element software, there is no element and material model to simulate the shape memory effect of SMA. Aiming at this problem and according to the particularity of SMA material, the method called “negative thermal strain” is proposed. Based on the experiment (namely the recovery stress and strain of SMA with original strain at different temperature are tested. Then the Young’s modulus of SMA at corresponding temperature is solved with constitutive equations), the simulation and analysis are carried out. Finally the deformation response curre of the structure is obtained. The forecasted result is close to the testing result, so the correctness of the method is validated. All of these can provide reference and gist for the design, simulation and fabrication of SMA driver.

Key words: Constitutive equations, Corrugated sheets structure, Numerical simulation, Shape memory alloy