梁撞击弹塑性波传播的动态子结构方法的研究

DYNAMIC SUBSTRUCTURE TECHNIQUE FOR PROPAGATIONS OF ELASTIC-PLASTIC WAVES OF BEAM INDUCED BY IMPACT

该文针对简支梁横向弹塑性撞击问题,建立动态子结构模型,推导了相应的动力学控制方程,并采用Newmark隐式积分法进行求解,将动态子结构方法应用于撞击激发弹塑性波传播问题的研究。考虑局部弹塑性接触变形,通过对撞击激发的弹塑性波传播,包括弯矩波、挠曲波、速度波和应力波传播过程的计算,研究动态子结构法分析弹塑性波的传播特征,弯曲波的弥散特征,以及塑性铰形成机理等的合理性。经过与三维动力有限元计算结果的比较表明,动态子结构方法可以合理地应用于柔性梁中弹塑性撞击瞬态波传播问题的研究。

The transverse struck of a simply supported beam caused by a rigid mass for a dynamic substructure model was built and the dynamic controlling equations were derived from finite element theory, to solve which the Newmark implicit integration method was applied. Then, a dynamic substructure technique was presented and applied to solve the propagations of elasto-plastic waves. Considering the local elasto-plastic contact deformation between the rigid mass and the beam, the calculations of the propagations of elasto-plastic waves by the dynamic substructure technique, including the bending moment wave, the flexural wave, the transverse velocity wave and bending stress waves, show the reasonable results of the propagations of elasto-plastic waves, dispersion of bending waves and formations of plastic hinges by the comparisons of those from the three-dimensional finite element method and rigid-plastic theory. Therefore, the presented dynamic substructure technique can be applied reasonably to the propagation of elasto-plastic waves induced by the impact along a flexible beam.