【作者】 王继明；

【导师】 王春生；

【作者基本信息】 长安大学 ， 桥梁与隧道工程， 2011， 硕士

【摘要】 HPS-485W高性能钢具有强度高、可焊性好、韧性好和耐候性显著等优点。随着高性能钢在公路桥梁中的应用与发展,对现行公路桥梁设计规范中钢材种类和条文进行更新已迫在眉睫。为了在公路桥梁中推广和安全地应用高性能钢,本文对HPS-485W高性能钢混合工字形梁进行了试验研究和有限元研究,分析了HPS-485W高性能钢混合工字形梁的失效机理,得到了影响HPS-485W高性能钢混合工字形梁抗弯强度与延性的各参数的影响规律与合理取值范围。本文的主要研究内容如下：1、通过通用有限元程序Ansys对Lehgih大学2根HPS-690W高性能钢等强梁进行有限元模拟分析,获得能够精确模拟试验梁受力性能的有限元模型,并对试验梁的失效机理进行了论述。2、通过材料拉伸试验,测试12mm厚HPS-485W高性能钢的材料力学特性,获得材料的全过程工程应力-应变曲线；通过对材料的工程应力-应变曲线数据处理,获得其真实应力-自然应变曲线、屈服强度和弹性模量等值。采用12mm厚HPS-485W高性能钢板和8mm厚Q235钢板设计了3根试验梁,并采用有限元模型对试验梁进行分析,根据捕捉到的试验梁失效模式,进行测点优化布置。3、对3根高性能混合设计钢梁进行了试验测试,对试验梁数据进行了分析处理,并与有限元模拟结果进行了分析比较,对试验梁的失效机理进行了深入研究。对比结果表明腹板屈曲强度对试验梁的抗弯强度具有显著影响。4、采用通过试验结果校核过的有限元模型对影响HPS-485W高性能钢混合工字形梁抗弯强度和延性参数进行了分析,确定了这些参数的一般影响规律及合理取值范围。这些参数包括翼缘宽厚比、腹板宽厚比、截面高宽比、几何初始缺陷分布模型、缺陷峰值、侧向约束形式、翼缘材料与腹板材料匹配等。最后对研究的内容进行了总结,并对下一步的研究提出了建议和思路。更多还原

【Abstract】 High Performance Steel (HPS) with yield strength of 485 MPa has high strength in addition to good weldability, fracture toughness, and corrosion resistance. As High Performance Steel plates are in use in highway bridges, the steel types and articles in bridge codes must be modified. To make the High Performance Steel paltes popularization and security application in highway bridges, testing study and finite elemet analysis were performed on hybrid I-girders fabricated from High Performance Steel plates in this paper, in addition, its failure mechanism had been studied, and at last, the influence rules and reasonable values of the paramerters were got. In detail, the following aspects were investigated:1. Finite element simulations were performed, as to two pieces of girders fabricated from HPS-690W and tested by professor Sause in Lehigh University, using the commercially general-purpose finite element program ANSYS9.0, to get the accurate finite element model for simulating the mechanical behavior of the specimens. And moreover the failure mechanism of the girders was in study.2. Material tesion test was performed to get the mechanic property of 12mm HPS-485W plates and the whole engineering stess-strain curve that was proceesed to obtain the true stress-nature strain curve, yield shtreng and young’s modulus. Three specimens were designed, in which 12mm HPS-485W plates and 8mm Q235 plates were used, and moreover simulated and analyzed by the finite element model wich was checked by test specimens tested by professor Sause to capture the failure modes and buckling location of the specimens. At last, typical measuring points of strain and deflection were determined.3. Three testing specimens by hybride design method were tested in bridge laboratory of Chang an University. The results of testing girders were processed, were compared with the results from finite element anslysis. And more over, the failure mechanism of specimens was studied in-depth. The compared results showed that the web buckling strength had notable effection on the flexural strength of high performance hybride girders.4. Parametric study about the effect of different parameters on the strength and ductility of hybrid I-girders fabricated from HPS-485W plates was performed by the checked finite element model. These parameters are the normalized flange slenderness, the normalized web slenderness,the cross section aspect ratio, geometric imperfections, lateral bracing system, match of the materials about flange and web and so on.In the end, the research contents of this paper were summarized, and the suggestion of the further study were given also.更多还原