钢纤维混凝土环向受拉全过程曲线试验研究

提出了研究钢纤维混凝土受拉性能的一种新的试验方法，成功地量测出钢纤维混凝土环向受拉的应力—应变全过程曲线；应用微裂缝开展理论，对钢纤维混凝土环向受拉全过程作了宏观过程和微观机理的分析；同时利用５组１０个不同纤维情况的环状试件的试验结果，对全曲线进行了数值模拟．     

型砂的高温变形及破坏方式

采用控制应变速率的方法测试了不同型砂高温下的破坏方式,从而获得了型砂全程应力-应变曲线;根据其应力-应变曲线,分析归纳了塑性及脆性材料高温下的蠕变模型及在生产中的应用。     

Kinetic theory of creep and creep-rupture strength analysis of structural components. Part 3. Upper and lower bounds for rupture onset time for non-uniformly heated structural components

Using Rabotnov’s kinetic theory of creep, an upper and lower bounds for a rupture onset time are derived for an arbitrary body (structural component) under stationary external thermomechanical loading. The bounds are then compared to those used in engineering practice. By way of illustration, the relevant results for a thick-walled non-uniformly heated pipe loaded by internal pressure are discussed. __________ Translated from Problemy Prochnosti, No. 1, pp. 32–40, January–February, 2006.     

Mechanical behavior of a composite printed-wiring-board material

This paper describes an experimental investigation of the mechanical behavior of a paper-filled-phenolic laminate widely used in the electronics industry. Uniaxial tensile tests in three directions, sandwich-beam bending tests to determine the compressive behavior, and cylindrical-punch punchability tests were conducted. Interesting phenomena observed included difference in tensile and compressive behavior, consistent crack branching in tension, and strain mismatch during punching. Based upon a thesis submitted by the first author in partial fulfillment of the requirements for the M.S. degreee in Mechanical Engineering at the University of Oklahoma, December 1976.     

Multichannel Strain and Temperature Measurement System for Structural Elements

he paper describes a 32-channel system for studying full-scale structures developed with the use of the state-of-the-art components. It provides continuous long-term measurement of strains and temperatures up to + 350°C and accumulation and storage of measurement data. The system was used to record the elastic strains and temperatures of a welded joint of the hot collector to the PGV-1000 steam generator nozzle in the period between the preventive maintenances. The measurement results reveal a complex pattern of strain and temperature distribution different from the axisymmetric one.     

基坑开挖土体切线模量取值的研究

基坑开挖过程中,土体的应力—应变关系不但具有非线性特点,还受应力路径的影响.今对基坑开挖过程中底部和周边土体这两种不同的卸荷应力路径下的应力应变关系进行了区分研究,并分别推导了其切线弹性模量的表达式,用于基坑工程的数值计算,并和常规加荷算法进行比较,结果表明:用本文建立的模量公式计算出的结果更接近工程实际.     

钢纤维混凝土轴心受拉性能试验研究

研制出应用辅助刚性架加载和两端埋设钢筋的变截面轴心受拉试件,在普通试验机上进行了钢纤维混凝土轴心受拉应力-应变全曲线测试试验,研究了钢纤维含量特征值、钢纤维类型对钢纤维混凝土轴心抗拉强度和应力-应变全曲线的影响规律,提出了钢纤维混凝土轴心抗拉强度计算公式和轴心受拉应力-应变全曲线的解析表达式,为工程应用提供了有价值的参考.     

三维无网格法与有限元法工程应用对比分析探讨

无网格伽辽金法基于移动最小二乘法的基础上,建立全计算域的高阶连续可导的插值函数,并只利用节点信息来建立离散模型的平衡方程。非线性有限单元法是在离散单元的基础上,构造连续可导的插值函数,进而建立平衡方程。本文应用无网格伽辽金法和非线性有限单元法及其相关理论编制三维计算程序,通过对工程算例的分析表明:无网格伽辽金法的计算精度高于有限单元法,应用于工程实例分析是有效可行的,已经成为有限单元法的有力补充。     

钢骨-方钢管混凝土轴压柱稳定承载力分析

钢骨-方钢管混凝土柱是一种组合柱设计模式,采用切线模量理论对该组合柱轴向受压稳定承载力进行分析.以核芯混凝土、方钢管和钢骨的应力-应变模型为基础,通过纵向变形协调和内外力平衡条件建立组合柱切线模量临界载荷的计算方法.由于核芯混凝土的应力-应变模型包含了方钢管的约束作用,因此该方法体现了组合柱中钢与混凝土之间的相互影响.7组轴心受压钢骨-方钢管混凝土长柱和41组方钢管混凝土长柱的试验结果表明,该方法可对轴压组合柱的稳定承载力给出良好预测.     

复杂应力状态下尼龙66力学性能研究

为了得到尼龙66试样在压缩以及复合压剪加载条件下的力学响应,采用国产三思万能试验机,并引入了2个带有双斜截面的金属垫块以及1个聚四氟乙烯套筒的特殊加载装置,对尼龙66试样进行复合压剪试验。此外,金属垫块的斜截面被加工成不同的倾斜角度θ(15°、30°、45°、50°和60°),通过调整角度获得了试样在不同压剪应力状态下的力学响应,并通过分析复合压剪加载时其受力情况得到其屈服行为。实验表明:尼龙试样的力学性能对剪切敏感并且随着剪切组分的增加而弱化,尼龙屈服行为与静水压具有相关性;同时验证了引入双斜面金属垫块的实验方式是一种能有效研究材料失效行为的测试方法。