【摘要】 采用DDA方法验证了1维应力波在不同边界的响应情况;在此基础上,实现了位移和应力2种地震波输入方式,并对2种方法进行了比较。基于DDA的1维计算模型,研究了在计算波动问题时块体单元尺寸和节理刚度的取值问题。研究结果表明:DDA模型网格在波传播方向的尺寸取最短波长的1/15～1/20;随着法向刚度的降低,节理对弹性纵波的衰减作用增大;当节理标准强度大于0.5时,DDA计算的节理面透射系数与理论透射系数的误差在5%以内。此外,基于DDA方法中波动问题的初步研究成果,对某地下厂房在正弦波作用下的动力响应情况进行了简单的分析,分析成果与有限元计算结果基本一致,这为DDA方法用于工程实例的动力响应分析奠定了基础。更多还原

【Abstract】 The responses of one-dimensional stress wave with different boundaries were verified using DDA method.On this basis,both the displacement and stress way to input seismic wave were achieved and compared.Based on the one-dimensional DDA model,the block element size and joint stiffness in wave calculation were studied.The results showed that the DDA model grid in the direction of wave propagation should take 1/15~1/20 of the shortest wavelength.The lower the joint stiffness is,the more observable the attenuation of elastic P-wave is.When the joint standard strength is greater than 0.5,the difference between DDA calculation and theoretical solution of transmission coefficient of joint surface is less than 5%.Based on the preliminary research results of wave problem in DDA method,the dynamic response of an underground house under sine wave was analyzed simply.The DDA result is consistent with the finite element solution,and it lays the foundation for dynamic response analysis of engineering case using DDA method.更多还原