大跨度球面网壳抗冲击性能研究

发布时间：2018-11-15 10:21

【摘要】：随着经济的不断发展,大跨度网壳结构在建筑工程实践中已得到非常广泛的运用。与此同时网壳结构越来越容易遭受冲击作用,冲击荷载作用时间短、峰值大,可能导致剧烈的损害以及给人们的心理带来极其严重的负面影响。由于计算机技术的不断完善,使用数值算法研究网壳结构的抗冲击成为可能。在网壳抗冲击领域,鉴于以前的学者研究的网壳跨度均较小,且研究对象仅限于单层网壳,远远不能满足实际大跨度网壳结构工程实践的需求,本文正是在此背景下,系统研究大跨度网壳的抗冲击性能,具体内容如下:1建立了单层球面网壳与双层球面网壳有限元模型本文介绍了有限元软件ANSYS/LS-DYNA中分析冲击作用的相关基础理论,定义了单元类型、材料属性,提出了基本假设,建立各种冲击荷载特征情况下的单层球面网壳与双层球面网壳合理数值分析模型。2研究冲击物尺寸与材料属性对网壳失效模式的影响本文研究了网壳结构失效模式随冲击物的尺寸以及材料属性等参数改变的变化规律,总结了网壳结构的失效模式与吸收冲击物动能的定性关系,探讨了冲击物尺寸效应与材料属性如何对网壳结构的失效模式形成的影响。3研究大跨度球面网壳结构冲击动力响应及失效模式分布结合冲击作用下球面网壳三种失效模式的典型算例,考察每种失效模式的冲击动力响应的特点。本文考察了屋面荷载、网壳跨度和杆件截面等参数变化对网壳结构失效模式的影响。4提出评价网壳抗冲击能力的新方法以冲击物的动能变化为基础,综合考虑不同冲击响应模式间的转换规律,结果表明,网壳结构的冲击响应模式随冲击物的动能呈规律性变化,进而提出一种评价的新方法。
[Abstract]:With the development of economy, long span latticed shell structure has been widely used in construction engineering. At the same time, the latticed shell structure is more and more vulnerable to the impact, the impact load time is short, the peak value is large, which may lead to severe damage and bring extremely serious negative impact to people's psychology. With the improvement of computer technology, it is possible to study the impact resistance of latticed shell by numerical algorithm. In the field of shock resistance of latticed shells, in view of the small span of latticed shells studied by previous scholars and the fact that the research object is limited to single-layer latticed shells, it is far from being able to meet the needs of the engineering practice of practical large-span latticed shell structures. The main contents of this paper are as follows: 1. The finite element models of single-layer reticulated shell and double-layer reticulated shell are established. In this paper, the basic theory of impact analysis in finite element software ANSYS/LS-DYNA is introduced. Defines the element type, material properties, presents the basic assumptions, The reasonable numerical analysis models of single-layer spherical reticulated shell and double-layer spherical reticulated shell under various impact load characteristics are established. 2 the effects of impact size and material properties on the failure mode of reticulated shell are studied in this paper. The pattern changes with the size of the impact material and the properties of the material. The qualitative relationship between the failure mode of latticed shell structure and the kinetic energy of absorbing shock is summarized. The influence of impact size effect and material properties on the formation of failure mode of reticulated shell structure is discussed. 3 the dynamic response of large span spherical reticulated shell structure and failure mode distribution combined with impact mode are studied. Typical examples of failure modes, The characteristics of impact dynamic response of each failure mode are investigated. In this paper, the influence of roof load, shell span and member section on the failure mode of latticed shell structures is investigated. 4 A new method for evaluating the impact resistance of latticed shells is proposed, which is based on the kinetic energy change of the impact material. Considering the transformation law of different shock response modes, the results show that the shock response modes of latticed shell structure change regularly with the kinetic energy of shock material, and a new evaluation method is put forward.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU399

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