防止压力容器塑性垮塌的分析方法研究

发布时间：2018-05-07 03:42

本文选题：应变线性化 + 当量结构应变准则　；参考：《北京化工大学》2015年硕士论文

【摘要】：压力容器的分析设计(DBA)作为规则设计(DBF)的并行设计方法越来越受到设计人员的重视,对于高温、高压容器或者规则设计所不能涵盖的非标设备,分析设计的使用尤为广泛。防止压力容器塑性垮塌失效是分析设计的重要任务之一,然而不同规范采用不同弹塑性分析方法。本论文通过数值分析的手段对六种重要弹塑性分析方法展开研究,主要包括以下内容：1.简要介绍欧盟EN13445-3标准附录B中总体塑性变形设计校核及其应用,通过对比二次外推法的两种外推方式得出以下结论：按EN13445外推法计算时,应首先将表面支点的应变分量二次外推到热点处,然后求热点处的主结构应变。2.提出基于应变线性化的主结构应变计算方法,根据建模方式的差异性对同一结构确定六种计算结构应变的方法,通过对比分析六种方法的计算结果得出：应变线性化方法与二次外推法所得结果偏差最小；应变线性化方法可以计算压力容器构件中任何位置的结构应变,包括二次外推法无法使用的情况。3.与EN13445直接法使用的最大主结构应变准则相对应,提出可以用于总体塑性变形校核的最大当量结构应变准则,该准则更适用于压力容器常用的韧性材料。4.实现了零曲率准则的程序化并给定了载荷——应变或者载荷——变形(P-w)曲线上零曲率点的判据,可以准确快速地判断P-w曲线上某点是否为零曲率点或者确定零曲率点在曲线上的位置,从而可以使用载荷-抗力系数法进行设计校核。5.通过对典型结构进行极限分析和弹塑性分析,对比六种弹塑性分析方法得出：零曲率准则为确定极限载荷的最佳准则；垮塌载荷和极限载荷确定许用载荷大小关系与结构的几何强化特性相关,故可以选择两者的较小值作为结构的最终许用载荷。
[Abstract]:Analysis and design of pressure vessels (DBA) is paid more and more attention by designers as a concurrent design method of regular design. It is widely used in analysis and design of high temperature, high pressure vessels or non-standard equipments that cannot be covered by regulation design. To prevent plastic collapse failure of pressure vessel is an important part of analysis and design, however, different methods of elastic-plastic analysis are used in different codes. In this paper, six important elastoplastic analysis methods are studied by means of numerical analysis, including the following contents: 1: 1. This paper briefly introduces the overall plastic deformation design verification and its application in Appendix B of EU EN13445-3 Standard. By comparing the two extrapolation methods of the quadratic extrapolation method, the following conclusions are drawn: when calculating with the EN13445 extrapolation method, First, the strain component of the surface fulcrum should be extrapolated to the hot spot, and then the strain of the main structure at the hot spot should be obtained. In this paper, a strain calculation method based on strain linearization is proposed. According to the difference of modeling methods, six methods for calculating the strain of the same structure are determined. By comparing and analyzing the results of the six methods, it is concluded that the strain linearization method has the least deviation from the quadratic extrapolation method, and the strain linearization method can calculate the structural strain at any position in the pressure vessel member. Including the second extrapolation method can not be used. 3. Corresponding to the maximum principal structure strain criterion used by EN13445 direct method, the maximum equivalent strain criterion, which can be used to check the total plastic deformation, is proposed. The criterion is more suitable for the ductile materials commonly used in pressure vessels. The program of zero curvature criterion is realized and the criterion of zero curvature point on load-strain or load-deformation P-w) curve is given. It can accurately and quickly judge whether a point on P-w curve is a zero curvature point or determine the position of zero curvature point on the curve, so the load-resistance coefficient method can be used to design and check. 5. Through limit analysis and elastic-plastic analysis of typical structures, six elastoplastic analysis methods are compared: zero curvature criterion is the best criterion for determining limit load; The relationship between the allowable load and the collapse load and the limit load are related to the geometric strengthening characteristics of the structure, so we can choose the smaller value of them as the final allowable load of the structure.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TH49

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