A method is proposed to identify the fully anisotropic elasticity tensor by applying the impulse excitation technique. A specially designed batch of several differently oriented bar-shaped specimens with rectangular cross section is analyzed with respect to the eigenfrequencies of their fundamental flexural and torsional modes. Estimations based on the equations for the calculation of the isotropic Young’s modulus and the shear modulus from the ASTM standard allow a first approximation of the elasticity tensor from a selected subset of the measured eigenfrequencies. Subsequently, a more precise determination of the elasticity tensor is achieved by a numerical modal analysis using the finite element method. In this course, a Newton–Raphson optimization method is applied to solve the inverse problem. The proposed approach is demonstrated on a batch of specimen fabricated from the nickel-base alloy IN718 by selective laser melting.

提出了一种应用脉冲激励技术识别完全各向异性弹性张量的方法。分析了一批专门设计的具有矩形横截面的几个不同取向的棒状试样的基本弯曲和扭转模式的特征频率。基于用于计算各向同性杨氏模量和来自 ASTM 标准的剪切模量的方程的估计允许根据测量的特征频率的选定子集对弹性张量进行第一次近似。随后，通过使用有限元方法的数值模态分析来更精确地确定弹性张量。在本课程中，应用牛顿-拉夫森优化方法来解决逆问题。