超弹性N形杆纯弯曲力矩理论建模和试验验证

Theoretical Modeling of Pure Bending Moment of Super-Elastic N-Shaped Boom and Its Experimental Verification

为了使N形杆在空间结构中顺利展开,对其缠绕过程中的力学特性进行了分析。基于协变基向量法建立了纯弯曲条件下各向同性单片带簧在缠绕时应变能理论模型,并采用最小势能原理推导了弯矩的理论模型,然后通过拟合曲率推导了N形杆缠绕时的理论模型。研制了4根N形杆样件,并搭建了试验平台,使用数显式推拉力计分别对杆件在缠绕过程的拉力进行了5次测试,然后求出峰值力矩,发现试验值与理论值的偏差不大于8.83%,偏差平均值为2.813%,从而验证了理论模型的准确性。该研究可用来分析超弹性杆在纯弯曲状态下的峰值力矩,对超弹性杆在宇航空间中的应用具有重大意义。

In order to make the N-shaped boom develop smoothly in the space structure,the mechanical properties of its winding process are analyzed.Based on the covariant basis vector method,a theoretical model of the strain energy of a isotropic single tape spring during winding under pure bending conditions is established,and the theoretical model of the bending moment is derived by using the principle of minimum potential energy,and then the bending moment of the N-shaped boom is derived by fitting the curvature.Four N-shaped boom samples are developed and an experimental platform is built.The tensile force of the four N-shaped booms during winding is measured(HP-10)for 5 times by using a digital display push-pull meter,respectively.And the peak torque is calculated.The result shows that the deviation between the experimental value and the theoretical value is no more than 8.83%and the average deviation is 2.813%,thus the accuracy of the theoretical model is verified.This study can be used to analyze the peak moment of the super-elastic boom in pure bending state,which is of great significance for the design of the super-elastic boom.