冲击荷载下网壳结构的失效机理研究

发布时间：2018-05-02 02:35

  本文选题：网壳结构 + 冲击　； 参考：《哈尔滨工业大学》2010年博士论文

【摘要】：随着大跨度网壳结构在重要大型公共建筑中的不断应用,人们开始考虑网壳结构在冲击、爆炸等偶然荷载下的性能。而尽管冲击荷载属于偶然荷载,近年来由于恐怖袭击等原因,发生概率不断增加;最为典型的是9.11事件,世贸双塔的设计代表了当代先进的设计水平,甚至曾考虑过Boeing707的撞击作用,但撞击及其并发作用仍然导致结构连续倒塌。此外,上世纪八十年代,一架轻型飞机坠入巴西圣保罗展览中心屋顶网架,也证明了飞行物撞击大跨结构的可能性。而目前国内外结构抗冲击的研究却比较滞后,网壳结构冲击响应的分析方法、失效模式及失效机理等许多问题亟待研究和解决。这些问题的研究不仅在网壳结构的抗冲击研究中有着迫切的需要,而且在类似的大型复杂结构抗冲击研究中也几乎处于空白阶段,有着广泛的研究前景和实际意义。鉴于上述原因,本文首先提出网壳结构冲击响应的分析方法,然后对冲击荷载下网壳结构的失效模式及其机理进行深入系统的研究,并通过大规模参数研究总结分析网壳结构的失效规律,此外,通过网壳结构缩尺模型的冲击试验验证了分析方法及分析结论的正确性,最后提出冲击荷载下网壳结构的防护设计建议。这些内容具体包括: 1.网壳结构冲击响应分析方法 本文建立了实用有效的网壳结构冲击响应分析方法,首先确定了网壳结构冲击响应研究的特征指标,包括荷载作用、网壳结构的特征响应两方面内容,然后探讨了网壳结构冲击响应的分析流程,并建立了网壳结构冲击响应分析的精确数值计算模型,此外,阐述了这一分析方法的具体实施过程; 2.冲击荷载下网壳结构的失效模式与机理 通过大量的参数计算研究网壳结构的冲击响应特性,总结分析了网壳结构冲击失效的四个典型算例,并分别以单层球面网壳和单层柱面网壳为例,详述了网壳结构冲击失效的全过程及其荷载作用与结构特征响应;然后依据不同冲击荷载下网壳的冲击失效特点,定义了网壳结构的三类失效模式,并根据冲击失效过程中的能量传递特点将冲击失效过程分为三阶段,同时揭示了每类失效模式对应的失效机理; 3.网壳结构冲击失效规律分析 通过大量的参数分析研究网壳结构的冲击失效规律,考察了结构最大响应/失效模式随网壳获取的总冲击能量的变化规律,并探讨了冲击物初动能对结构最大响应/失效模式的影响;此外,提出用整体倒塌失效系数作为结构抗冲击能力的评定指标,然后通过变化荷载与结构参数对冲击荷载下网壳结构的整体倒塌失效规律进行大量的参数分析,确定了易于产生整体倒塌的初始冲击条件。 4.网壳结构冲击试验研究 为验证网壳结构冲击响应分析方法及分析结论的正确性,对Kiewitt-6型单层球面网壳缩尺模型进行了系统的试验研究,试验内容包括模态分析、弹性冲击试验与破坏性冲击试验三部分,通过试验与数值结果(包括频率、振型、冲击力、杆件应力与破坏形态)的对比分析,证明了本文提出的分析方法及分析结论的正确性,此外,通过对比分析探讨了冲击物初始偏转、支座约束条件、加工误差、阻尼力等因素对结构最大冲击响应的影响原因及影响程度。 5.冲击荷载下网壳结构的防护设计方法及建议 以网壳结构的冲击失效机理与冲击失效规律为理论基础,以防止结构在冲击荷载下出现整体倒塌为防护目标,提出冲击荷载下网壳结构的三种防护设计方法:轻屋面、整体加强法和临界位置加强法,并分别对三种方法的防护效果进行对比分析;在此基础上,综合考虑防护效果与经济条件,提出冲击荷载下网壳结构的防护设计建议;与前文内容相结合,形成了完整的网壳结构抗冲击研究的理论框架。
[Abstract]:With the continuous application of the large span reticulated shell structure in important large public buildings, people began to consider the performance of the reticulated shell under accidental loads such as shock and explosion. Although the impact load belongs to the accidental load, the probability is increasing in recent years because of terrorist attacks. The most typical one is the 9.11 event, the design of the world trade trade Twin Towers. It represents the advanced level of contemporary design, even considering the impact of Boeing707, but the impact and its concurrency still lead to the continuous collapse of the structure. In 80s, a light aircraft crashed into the roof truss of the Brazil St Paul Exhibition Center and proved the possibility of flying objects hitting the large span structure. The research on the impact resistance of the outer structure is lagging behind. Many problems such as the analysis method of the impact response of the reticulated shell structure, failure mode and failure mechanism are urgently needed to be studied and solved. The research of these problems not only has an urgent need in the study of the impact resistance of the reticulated shell structure, but also is almost the same in the research of the similar large-scale complex structure impact resistance. In the blank stage, there are extensive research prospects and practical significance. In view of the above reasons, the analysis method of the impact response of the latticed shell structure is first proposed. Then the failure mode and the mechanism of the reticulated shell structure under the impact load are systematically studied, and the failure law of the reticulated shell structure is summarized and analyzed through the large-scale parameter study. In addition, the correctness of the analysis method and analysis conclusion is verified by the impact test of the scale model of the reticulated shell structure. Finally, some suggestions on the protective design of the reticulated shell structure under the impact load are proposed.
Analysis method of impact response of 1. reticulated shell structure
In this paper, a practical and effective method to analyze the impact response of the reticulated shell structure is established. First, the characteristics of the impact response of the reticulated shell structure are determined, including the load action, the characteristic response of the reticulated shell structure in two aspects. Then the analysis process of the impact response of the reticulated shell structure is discussed, and the exact number of the impact response analysis of the reticulated shell structure is established. The value calculation model, in addition, expounds the concrete implementation process of this analysis method.
2. failure modes and mechanisms of reticulated shells under impact loading
The impact response characteristics of the reticulated shell structure are calculated and studied by a large number of parameters. Four typical examples of the impact failure of the latticed shell structure are summarized and analyzed. The whole process of the impact failure of the latticed shell structure and the response of the load and structure characteristics are described in detail, and the different impact load is then based on the different impact load. Under the impact failure characteristics of the reticulated shell, three types of failure modes of the reticulated shell are defined, and the impact failure process is divided into three stages according to the energy transfer characteristics in the process of impact failure, and the failure mechanism corresponding to each type of failure mode is revealed.
Analysis of impact failure law of 3. reticulated shell structure
The effect of the maximum response / failure mode on the total impact energy obtained by the reticulated shell is investigated through a large number of parameters analysis, and the influence of the initial kinetic energy of the impact on the maximum response / failure mode of the structure is discussed. Furthermore, the overall collapse failure coefficient is proposed as the anti impact capacity of the structure. According to the evaluation index, a large amount of parameter analysis is carried out on the failure law of the overall collapse of the reticulated shell structure under the impact load, and the initial impact conditions that are easy to produce the overall collapse are determined by the change load and the structural parameters.
Study on impact test of 4. reticulated shell structure
In order to verify the correctness of the analysis method and conclusion of the impact response of the reticulated shell structure, the experimental research on the scale model of Kiewitt-6 type single-layer spherical reticulated shell is carried out systematically. The test contents include three parts: modal analysis, elastic impact test and destructive impact test, and through the test and numerical results (including frequency, vibration mode, impact force, bar parts) The comparison and analysis of force and failure form proves the correctness of the analysis method and analysis conclusion proposed in this paper. In addition, through comparative analysis, the influence causes and influence degree of the initial deflection of the impact material, the bearing constraint conditions, the machining error, the damping force and other factors on the maximum impact response of the structure are discussed.
5. protective design methods and suggestions for reticulated shell under impact load
Based on the theory of the impact failure mechanism and the impact failure law of the latticed shell structure, in order to prevent the structure from collapse as a protective target under the impact load, three protective design methods of the shell structure under the impact load are put forward: the light roof, the integral method and the critical position strengthening method, and the protective effects of the three methods are respectively carried out. On this basis, on this basis, the protective effect and the economic conditions are taken into consideration, and the protective design proposal of the reticulated shell structure under the impact load is proposed, and a complete theoretical framework for the study of the impact resistance of the reticulated shell structure is formed with the previous content.

【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2010
【分类号】：TU399

【引证文献】

中国期刊全文数据库 前5条

1 王多智;范峰;支旭东;戴君武;;冲击荷载下网壳结构的失效模式及其动力响应特性[J];工程力学;2014年05期

2 王秀丽;马肖彤;李俊杰;;基于不同加载点的冲击荷载作用下单层球面网壳结构动力响应研究[J];空间结构;2014年02期

3 王多智;范峰;支旭东;戴君武;曹正罡;杜修力;;网壳结构冲击失效规律分析[J];土木工程学报;2012年S2期

4 王多智;范峰;支旭东;戴君武;;冲击荷载下单层凯威特型球面网壳防护方法及建议[J];振动与冲击;2012年08期

5 王秀丽;马肖彤;;冲击荷载作用下受损网壳结构全过程动力响应分析[J];建筑科学与工程学报;2013年03期

中国重要会议论文全文数据库 前3条

1 林莉;范峰;支旭东;尹弘峰;沈世钊;;冲击物尺寸对K8型网壳失效模式影响研究[A];第十四届空间结构学术会议论文集[C];2012年

2 林莉;范峰;支旭东;尹弘峰;沈世钊;;冲击物弹塑性对K8型网壳失效模式影响研究[A];第十四届空间结构学术会议论文集[C];2012年

3 马肖彤;王秀丽;吴长;;单层网壳结构在不同加载点冲击荷载作用下的动力响应分析与试验研究[A];第23届全国结构工程学术会议论文集（第Ⅲ册）[C];2014年

中国博士学位论文全文数据库 前1条

1 吴长;强震和冲击荷载下球面网壳的动力失效分析与试验研究[D];兰州理工大学;2014年

，

本文编号：1832025