应力吸收层原材料选择标准的探讨

应力吸收层是一种新型的延缓和防止反射裂缝的结构材料,在原材料的要求方面有很多特点,我们结合室内试验对应力吸收层原材料选择标准进行了较深入的研究,并取得了一定的成果。     

CFPR加固混凝土桥梁的端部应力分析

CFRP加固混凝土桥梁是一项新的应用外粘高性能复合材料加固结构技术,本文基于国内外关于CFRP片材加固混凝土梁的理论,对加固结构中的CFRP端部应力集中规律进行计算,在此基础上分析了加固后的桥梁在车辆动载作用下端部应力的变化规律。     

斜梁桥力学特性分析

基于有限元理论,借助大型有限元通用计算程序,对某简支斜箱梁桥的静动力特性进行了分析研究,并将其与等宽同跨径的正桥的力学特性进行了对比,得出斜箱梁桥特有的应力分布规律、动力特性以及空间作用效应规律,研究的结论,可为该类桥型的设计提供重要参考依据。     

Approximate weight functions of stress intensity factor for a wide range shapes of surface and an embedded elliptical crack

This paper describes the application of weight function for stress intensity factor in a surface crack with a wide range of crack shapes. Based on the weight function representation proposed by Wang and Glinka (2009), an extended formulation of the weight function for surfaces and embedded cracks is performed. The unknown parameters in the formulations were determined from reference values of stress intensity factor for a surface and an embedded crack given by finite element analysis with the J integral method. The effectiveness of the proposed weight functions has been verified by comparing with the stress intensity factors given by finite element analysis and available approximated solutions under several loading conditions.     

海员心理健康的研究

本文对海员心理健康研究方法、海员心理健康现状及其影响因素、海员心理卫生保障等方面进行了回顾与展望，提出了保障海员心理卫生的相关建议，为海员心理健康的深入研究提供借鉴。     

集装箱船扭转强度和加强方式研究

介绍约束扭转计算原理,分析集装箱船的结构和受力特点,利用MSC/Nastran软件探讨了集装箱船的扭转强度计算方法。在现有结构形式的基础上,提出几种可能提高结构扭转强度的结构加强方案,通过有限元分析比较各方案对于增加同样重量的钢料船体结构中翘曲应力变化情况,比对抗扭效果,研究在考虑成本基础上提高集装箱船抗扭强度的加强方案优先顺序,结果显示对于支线型集装箱船增加舱口围厚度可更有效提高其抗扭强度。     

The effect of weld residual stress on fracture toughness at the intersection of two welding lines of offshore tubular structure

Due to the spatial complexity and fabrication characteristics of offshore platforms, it is inevitable to encounter overlaps or proximity of weld lines in tubular joints. Several international standards such as American Petroleum Institute (API), American Welding Society (AWS), and American Institute of Steel Construction (AISC) regulate the minimum distance between primary weld beads; however, any logical and detailed background of this limitation has not been presented. For a non-compliant weld joint where the regulation is not met, fracture toughness calculation is a typical index to verify the structural integrity.This research consists of two parts. First, weld residual stress distributions are calculated by a 3D thermo-mechanical nonlinear Finite Element Analysis. Two crossing welds, a T-weld crossing on a butt weld, are simulated in one model. A separate tee and a butt welding simulations are also performed for a comparative purpose. Second, SIFs and J-integral values are calculated at the surface and deepest crack tip locations for four different types of semi-elliptical surface cracks. Four cracks are embedded into the weld model and the residual stress distribution from the 3D thermo-mechanical FEA are mapped to a 3D FE crack model as initial conditions. An additional axial tensile load is also imposed. SIF values are compared with those using the weighting function method for the butt weld model subject to three load cases, i.e., tensile stress only, weld residual stress only, and both of them. From the simulation, a tubular joint containing a chord girth weld intersected with weld beads of brace is found to show lower the SIF values than that having only a girth weld on chord.     

GSOG应力吸收层抑制反射裂缝能力的研究

在杨高路大修工程中使用一种新型间断半开级配的沥青混合料(GSOG)充当应力吸收层,分散板块间的水平温缩应力与竖向剪切力共同作用下的应力集中,延缓反射裂缝产生的速度.经高温稳定性、低温约束试件及嵌入式轴向加载试验,均有良好表现,对比AC-20试验段,证明它具备良好的分散应力集中的能力.     

丙烯酸泡棉胶带在汽车结构优化方面的应用

丙烯酸泡棉胶带在优化汽车结构方面已经成为了一种越来越重要的方式。为了更好地提供在汽车优化结构设计方面的选择,文章介绍了丙烯酸泡棉胶带的发展及其性能特点,针对汽车结构设计的优化,通过对丙烯酸泡棉胶带固定方式和传统机械固定方式的比较和分析,同时也通过两者在提高整车密封性能和降低整车质量方面的比较和分析进一步说明丙烯酸泡棉胶带在汽车内外饰连接固定的方式和汽车结构设计的方面提供了更加优化、更加经济和更加环保的选择。     

长短桩复合地基桩土荷载分担比研究

对长短桩复合地基在竖向荷载作用下的力学性状进行了研究,揭示了长短桩复合地基在不同桩土刚度比条件下桩土相互作用、荷载分担比、桩土应力比及荷载传递方面的变化规律。试验结果表明,此类复合地基能使刚性桩、柔性桩以及土体协调变形,合理发挥它们各自的承载能力,为今后的设计和推广应用提供了依据。