CAJ | 학술논문

从杆的纵向振动方程出发,建立了其相应的有限元动力学方程,利用直接积分法计算了杆在外激励下的振动响应.将杆的局部损伤模拟为单元抗拉刚度的减少,推导了响应对单元抗拉刚度的灵敏度,并利用此响应灵敏度进行杆的局部损伤识别.数值算例表明,该文方法能快速准确地识别出杆的局部损伤,并且对模拟的人工噪声不敏感,说明本文方法具有一定的工程应用前景.
종간적종향진동방정출발,건립료기상응적유한원동역학방정,이용직접적분법계산료간재외격려하적진동향응.장간적국부손상모의위단원항랍강도적감소,추도료향응대단원항랍강도적령민도,병이용차향응령민도진행간적국부손상식별.수치산례표명,해문방법능쾌속준학지식별출간적국부손상,병차대모의적인공조성불민감,설명본문방법구유일정적공정응용전경.
The dynamic equation of rods for finite element calculation is obtained from the longitudinal vibration analysis of rod. The dynamic response of a rod under external force is calculated from the Newmark direct integration method. The local damage in the rod is simulated by a reduction in the elemental tensile stiffness. The dynamic response sensitivity with respect to the physical parameter (elemental tensile stiffness) is derived. In the inverse analysis, the local damages in the rod are identified from dynamic response sensitivity-based finite element model updating method. It is found that the local damage(s) can be identified successfully from the time histories of several nodes. The effect of artificial measurement noise on the identified results is also discussed. Numerical simulation shows that the proposed method is effective for damage detection and it is insensitive to the artificial measurement noise. Thus it has the potential for practical applications.