K8型单层球面网壳抗冲击荷载性能研究

PERFORMANCE FOR KIEWITT8 SINGLE-LAYER RETICULATED DOMES SUBJECTED TO IMPACT LOAD

首先介绍了求解冲击问题的解析法、有限元法的算法基础、适用于求解强非线性动力问题的有限元解法,以及计算冲击荷载响应的通用有限元软件ANSYS/LS-DYNA。为验证软件求解功能及相关参数设置的正确性,分别用解析法与有限元软件求解同一简单模型,二者结果吻合。随后在ANSYS/LS-DYNA软件中建立了60m跨度K8型单层球面网壳冲击模型。在上述基础上,对135个K8型网壳算例进行了分析,研究表明:网壳竖向变形和主要杆件受力随冲击质量与速度的增加而增大,当质量与速度增加到一定值后,二者均不再变化。而且当冲击质量较小时,网壳塑性发展可以由冲击动量初步判定,冲击质量较大时,则与冲击速度之间有明显相关性。在一次冲击网壳破坏情况下,冲击持时随冲击速度的增大而减少。

The paper presents the analytic method, theory and basic solutions of FEM adapted to solve non-linear dynamic problems, as well as ANSYS/LS-DYNA, a finite element software used both domestically and abroad. Then it gives solutions for one simple model by the analytic method and by ANSYS/LS-DYNA respectively in order to validate functions of software and parameters selected. The two kinds of solutions are consistent. Afterward, it gives the model of Kiewitt8 single-layer reticulated dome whose span is 60m. On the basic 135 examples, it is shown that the vertical displacement and stress of main elements increase when increase the impact mass or impact velocity, but they do not change if the impact mass or the impact velocity is big enough. The plastic development has close relation to the impact momentum for a little mass impact, as have close relation to the impact velocity for the great mass impact. Then the much impact velocity conduces the short impact duration, if Domes are destroyed by a single impact.