MATLAB在结构可靠度分析中的应用

以某砌石重力坝为例,利用结构可靠度计算方法中的JC法和Monte-Carlo法进行可靠度分析,建立结构功能函数,利用MATLAB数学软件分别对JC法和Monte-Carlo法进行编程计算,得到砌石重力坝的失效概率与可靠度指标.运行结果表明运用MATLAB编程计算精度较高,运行速度较快.     

基于MATLAB的结构可靠度分析方法研究

基于结构可靠度分析方法—JC法、蒙特卡罗法和响应面法的基本原理,利用MATLAB软件对算例编制了相应计算程序,并对计算结果进行了比较.计算结果表明,利用MATLAB可以编制结构可靠度分析程序,计算结果较快,数据合理,并为复杂结构的可靠性分析提供参考.     

裂纹体流变可靠性研究与应用(Ⅱ)

本文对文[1]所提出的理论模型,用JC法进行了流变可靠性计算,反映了流变可靠指标βR明显的时间相依性,得出了流变极限可靠指标βRL的概念;并应用于工程计算中,对建筑结构设计规范和水工结构规范的修定有一定的参考价值。     

CFRP加固混凝土柱抗剪承载力可靠度分析

基于结构可靠度的理论，采用JC法对CFRP加固混凝土柱的抗剪承载力可靠指标进行一些探讨。     

非时标网络计划中自由时差计算的一种推荐方法

通过对网络图进行时差计算,可以抓住主要矛盾,向非关键工作要人力资源,加快施工进度,很好地控制工程工期,确保按时完成施工任务。然而很多计算方法均不如意,因此这里推荐一种计算方法———时间间隔法。经过多年的反复检验,证明该法是一种不错的计算方法。     

差量法在解化学计算题中的应用

差量法是利用化学反应前后某些成分在物质的量、质量、体积等的变化来进行解题的有效方法.这种方法很多时候也给大家的解题带来便利,可将两个反应的计算合为一个.在高中化学解题过程中常常要用到差量法,以减少大量的计算过程.而我们在教学时要引导学生恰当使用差量法,为解题服务.在学习时要注重归纳与分析,总结各个类型的差量法     

基于广义随机空间内的结构体系可靠度分析

在结构系统的可靠度计算过程中,当随机变量为相关的非正态分布时,利用正交变换或Rosenblatt变换计算其可靠指标,计算量较大。采用在广义随机空间内计算各机构可靠指标,然后利用PNET法计算结构体系可靠度,计算简便,精度也满足要求。     

可能自我测量方法述评

Markus和Nurius在1986年正式提出可能自我的概念,希望自我、预期自我和恐惧自我是可能自我理论的横向结构,而过去自我、现在自我和未来自我是可能自我理论的纵向维度.目前,可能自我测量的方法主要有问卷法、结构访谈法、Q分类法、叙事法等.测量可能自我的方法各有各的步骤、特点.研究者选择方法时易受自身对可能自我认知的影响,因此,在方法的选择上,研究者可考虑将不同评估方法结合适用,同时选用的被试要合适.     

多轴挂车转向机构设计方法与计算程序

分析了多轴液压悬挂挂车转向系统的结构,推导出了转向机构各部件之间的运动关系式,在此基础上给出了这类挂车转向系统机构设计的计算方法,并用matlab实现了该计算方法;通过对某种国产拼接式多轴挂车转向机构的计算,证明了该方法的合理性和实用性。     

三维粘弹塑性有限元凝聚法研究复杂坝基开挖

为探讨坝基开挖对建基面和坝肩稳定的影响 ,建立粘弹塑性模型 ,用有限元凝聚法对坝基开挖稳定问题进行分析计算 ,研究了建基面及软弱结构面与时间因素有关的位移、应力、屈服破坏的动态过程 .结果表明 ,采用的理论和计算方法合理 ,计算程序具有精度高 ,收敛速度快等特点 ,展示了良好的应用前景     

黑山湖特大桥跨兰新铁路零号块临时固结计算

连续梁桥墩和梁存在支座,是铰接关系。而连续梁桥采用悬臂施工在没有合拢前是悬臂状态,为了保证挂篮施工过程的安全性,必须对连续梁桥墩和梁进行临时固结处理。因此临时固结成败直接关系着连续梁悬臂施工的安全和稳定。本文结合黑山湖跨兰新铁路立交特大桥,分析连续梁桥临时固结的设计计算。     

Shear behavior of novel prestressed concrete beam subjected to monotonic and cyclic loading

Prestressed steel ultrahigh-strength reinforced concrete (PSURC) beam is a new type of prestressed concrete beam, which not only has a considerable compressive strength attributed to the ultrahigh strength concrete, but also ensures a certain degree of ductility at failure due to the existence of structural steel. Five of these beams were monotonically tested until shear failure to investigate the static shear performance including the failure pattern, load-deflection behavior, shear capacity, shear crack width and shear ductility. The experimental results show that these beams have superior shear capacity, crack control ability and shear ductility. To study the shear performance under repeated overloading, seven PSURC beams were loaded in cyclic test simultaneously. The overall shear performance of cycled beams is similar to that of uncycled beams at low load level but different at high load level. The shear capacity and crack control ability of cycled beams at high load level are reduced, whereas the shear ductility is improved. In addition, the influences of variables including the degree of prestress, stirrup ratio and load level on the shear performance of both uncycled and cycled beams were also discussed and compared, respectively.     

阶梯形变截面梁的弯曲变形

提出了计算阶梯形变截面梁弯曲变形的一种新方法．算例表明，本文方法和结果对静定和超静定梁均适用，并且计算简捷，便于应用．     

Shear strengthening of pre-damaged reinforced concrete beams with carbon fiber reinforced polymer sheet strips

This paper presents the results of an experimental investigation on the response of pre-damaged reinforced concrete (RC) beam strengthened in shear using applied-epoxy unidirectional carbon fiber reinforced polymer (CFRP) sheet. The reasearch included four test rectangular simply supported RC beams in shear capacity. One is the control beam, two RC beams are damaged to a predetermined degree from ultimate shear capacity of the control beam, and the last beam is left without pre-damaged and then strengthened with using externally bonded carbon fiber reinforced polymer to upgrade their shear capacity. We focused on the damage degree to beams during strengthening, therefore, only the beams with side- bonded CFRPs strips and horizontal anchored strips were used. The results show the feasibility of using CFRPs to restore or increase the load-carrying capacity in the shear of damaged RC beams. The failure mode of all the CFRP-strengthened beams is debonding of CFRP vertical strips. Two prediction available models in ACI-440 and fib European code were compared with the experimental results.     

Behavior of preloaded RC beams strengthened with CFRP laminates

INTRODUCTION Externally bonded fiber reinforced polymer (FRP) composites can be used to improve the flexural strength of structural members. To evaluate the flex-ural performance of the strengthened members, it is necessary to study the flexural stiffness of FRP- strengthened RC members at different stages, such as pre-cracking, post-cracking and post-yielding. Up to now, only very few studies were focused on the structural members strengthened under pre-loading or pre-cracking (Arduin…     

基于ANSYS程序的钢筋混凝土梁非线性数值模拟

采用商用程序ANSYS对不同配筋率的钢筋混凝土梁进行非线性数值分析，以考察不同配筋率对钢筋混凝土梁受弯性能的影响。结合数值模拟分析过程，详细介绍了基于ANSYS程序的钢筋混凝土构件非线性数值分析的关键技术，分析了对不同配筋率的钢筋混凝土粱的刚度变化、破坏特征、截面应力分布、裂缝发展和钢筋、混凝土应力及应变发展过程。     

新型组合钢连梁抗震性能研究

通过含有钢筋混凝土连梁、钢连梁与新型组合钢连梁的结构进行试验对比,利用ANSYS软件建立试验模型,进行模拟试验分析,研究新型组合钢连梁在弹性状态下的抗震性能。试验结果表明:小跨高比连梁采用新型组合钢连梁具有明显的减振效果,抗震性能好,适宜剪力墙结构采用。     

New Factor to Characterize Mechanism of “Strong Column-Weak Beam” of RC Frame Structures

Most reinforced concrete(RC)frame structures did not achieve the "strong column-weak beam" failure mode in recent big earthquakes, resulting in a large number of casualties and significant property loss. To deal with this serious problem, a new column-beam relative factor was proposed to characterize the relative yield situation of column ends and beam ends. By limiting the column-beam relative factor, RC frame structures could achieve the "strong column-weak beam" failure mode under the excitation of strong ground motions. The limit values of column-beam relative factor were calculated, analyzed and verified by using structural simulation models for corner columns in the bottom story of structures, which are destroyed most seriously in earthquakes. The results show that the limit values should be analyzed under bi-directional ground motion and with different axial compression ratios of columns. The peak ground acceleration(PGA)of ground motions has no significant effect on the limit values, while the type of strong ground motions has a significant effect on the limit values.     

外包钢-混凝土连续组合梁的负弯矩极限承载力(英文)

对2根外包钢-混凝土连续梁试件进行了静力加载实验研究与承栽力分析.测量并分析了试件的荷栽-挠度及荷载-应变关系曲线.结果表明:外包钢-混凝土组合梁负弯矩区钢筋和外包钢梁通过抗剪连接措施能有效地共同工作,整体工作性能良好.在承栽能力极限状态,负弯矩和正弯矩最大截面的塑性应变均充分发展,并形成比较理想的塑性铰.随着配筋率的提高,组合梁受弯承栽力明显提高,而延性和转动能力相应降低.在试验数据基础上,给出了外包钢-混凝土组合梁在负弯矩区极限受弯承载力的计算公式,计算结果与实验结果吻合良好.     

GFRP加固混凝土梁受弯性能试验研究

对15根玻璃纤维布加固的钢筋混凝土梁进行了试验研究。试验结果表明,玻璃纤维布加固的钢筋混凝土梁抗弯承载力显著提高,加固效果明显,但要有足够的粘贴长度以避免发生剥离破坏。