高强度结构钢材材料设计指标研究

发布时间：2018-01-09 06:20

  本文关键词：高强度结构钢材材料设计指标研究　出处：《清华大学》2015年硕士论文　论文类型：学位论文

  更多相关文章： 高强钢 GJ钢 可靠度 抗力分项系数 本构模型

【摘要】：高强度结构钢材以其良好的力学性能和可加工性能,已经逐步开始在建筑结构和桥梁结构中得到应用。已有的研究表明,高强钢结构构件的受力性能与普通钢材构件存在一定的差异,因而相应的设计方法发生了改变。目前,我国新修订的钢结构设计规范已经给出了460MPa强度级别钢材的抗力分项系数和强度设计值,但更高强度级别钢材的设计指标还没有提出。同时,国产的GJ系列钢材也在结构工程中有了很多应用,但目前相关设计规范中只有Q345GJ钢的设计指标。本文以《高强钢结构设计规程》的编制为背景,通过试验研究、数值模拟和理论分析等方法研究了不同等级的高强度结构钢材和GJ系列钢材的可靠度,计算了其强度设计指标,同时研究了高强度结构钢材在单调荷载作用下的本构模型。主要包括以下内容:(1)调研收集了高强度结构钢材(Q500、Q550和Q690)材料力学性能数据11638组和GJ系列钢材(Q390GJ、Q420GJ和Q460GJ)数据2912组。对高强钢和GJ钢开展独立的材性试验79组。同时开展了加载速率和试验机柔度对高强钢屈服强度影响的试验。利用数理统计方法,综合考虑上述调研和试验数据,得到了高强钢和GJ钢材料性能不定性的统计参数。(2)利用通用有限元软件ABAQUS建立有限元模型,经已有试验数据验证后,计算了高强度钢材(Q500、Q550、Q620和Q690)焊接截面压弯构件弯矩作用平面内的极限承载力880组、受弯构件整体稳定承载力460组。通过已有研究的数据、数值模拟的数据和规范公式计算值的比较,计算得到了高强钢轴心受压构件、压弯构件和受弯构件的计算模式不定性的统计参数。(3)基于上述结果和已有研究数据,采用可靠度理论中的一次二阶矩法,通过数学软件Matlab编制程序,提出了高强度结构钢材和GJ系列钢材的抗力分项系数建议值,并对其进行了可靠度校核分析。(4)总结已有研究中高强度结构钢材的材性数据,并利用开展的高强钢材性试验获得的数据,更新了高强钢多折线本构模型的参数,以Ramberg-Osgood模型为基础标定了适用于高强钢的非线性本构模型,同时提出了修正的高强钢多折线本构模型。
[Abstract]:Because of its good mechanical properties and machinability, high strength structural steels have been gradually applied in building structures and bridge structures. The mechanical behavior of high strength steel structure members is different from that of ordinary steel members, so the corresponding design method has been changed. The new revised steel structure design code in China has given the resistance factor and strength design value of 460MPa strength grade steel, but the design index of higher strength grade steel has not been put forward. Domestic GJ series steels have been widely used in structural engineering, but only Q345GJ steel is used in the relevant design code. The background of this paper is the compilation of structural design rules for high strength steel. Through experimental research, numerical simulation and theoretical analysis, the reliability of high strength structural steels and GJ series steels of different grades are studied, and the strength design indexes are calculated. At the same time, the constitutive model of high strength structural steel under monotonic load is studied. Q550 and Q690) material mechanical properties data 11638 groups and GJ series steel Q390GJ. Q420GJ and Q460GJ). Data 2912 groups. 79 groups of independent tests on high strength steel and GJ steel were carried out. At the same time, the effect of loading rate and machine flexibility on yield strength of high strength steel was tested. The statistical parameters of high strength steel and GJ steel with uncertain properties are obtained by considering the above investigation and test data. The finite element model is established by using the general finite element software ABAQUS. After being verified by experimental data, 880 groups of ultimate bearing capacity of high strength steel Q500 Q550Q620 and Q690) in the bending moment plane are calculated. The overall stability bearing capacity of the flexural members is 460 groups. Through the comparison of the existing data, numerical simulation data and the calculated values of the standard formula, the axial compression members of high strength steel are calculated. Based on the above results and existing research data, the first-order second-order moment method of reliability theory is used. Based on the program of Matlab, the suggested values of resistance coefficient of high strength structural steel and GJ series steel are put forward. And the reliability check analysis. 4) summarize the data of high strength structural steel in the existing research, and use the data obtained from the high strength steel property test. The parameters of the multifold constitutive model of high strength steel were updated and the nonlinear constitutive model suitable for high strength steel was calibrated based on Ramberg-Osgood model. At the same time, a modified multi-fold constitutive model of high-strength steel is proposed.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU511.3
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本文编号：1400318