爆炸荷载下RC梁系的解析分析

ANALYTICAL SOLUTION OF RC BEAM SYSTEM UNDER EXPLOSION LOADING

对梁系结构在爆炸荷载作用下的动力计算问题进行了研究,由于支承构件的变形性,梁系结构可归结为第二类的动支座问题。建立了梁系的动支座计算模型,推导并给出了梁系结构分别在弹性阶段和塑性阶段的动力计算公式,分析了影响梁系振动的主要因素和影响规律。研究表明:影响梁系结构振动的主要因素有两个,下部支承结构的基频ω0和无量纲参数ωθ,基频ω0和参数ωθ越大,上部构件的动力系数就越大。当ω0≥5ω时,下部构件对梁系振动的影响可忽略,认为上部构件是刚性支承。

Dynamic analysis of a RC beam system under explosion loads is performed in this paper. The beam system can be classified as the second type beam with flexible supports. Computational model for the RC beam system has been established, and then formulae for the dynamic analysis of the beam system in elastic stage and plastic stage are deduced. Governing factors and their effects on the dynamic responses of the beam system are also discussed. The study indicates that the structural vibration of the beam system depends mainly on the fundamental frequency of supporting member wθ and the parameter wθ. The higher the fundamental frequency and parameter coo, the larger the dynamic coefficient. The effect of supporting member can be neglected when w0 ≥ 5w, and assumed to be rigid.