Theoretical modeling and finite element analysis of planar tensile compliant joint

In LEMs (Lamina Emergent Mechanisms), LET (Lamina Emergent Torsion) is one of the commonest compliant joint, but the limit of its structure makes it ill afford the tensile stress. The LET is promoted under the condition of invariable rotational stiffness, in order to adapt it to the condition existing the axial load which means amplify the axial stiffness of the structure. Base on the above structure, it can be equivalent to a spring model. After developing the theoretical models of the spring, the closed-form solution would be obtained. Then the paper analyzes deformation of the rotating load and axial load through establishing the FEA model by ANSYS and compares with previous theoretical models. It is proved the equivalent stiffness solution of spring model is consistent with simulation results. In addition, under the nearly invariable rotation stiffness the small deformation of the LET is identical with expectation when tensile stress is applied.