[书]PERFORM-3D原理与实例 – 第7章 – 填充墙模拟

在传统的结构分析中,填充墙通常作为非结构构件考虑,在分析过程中,将其以外荷载的形式施加到结构上,并对整体结构的周期进行折减以考虑填充墙对结构刚度的贡献,未直接考虑填充墙对结构非线性行为的影响。相关研究表明[1,2],填充墙对结构的抗震性能有着重要的影响,在结构弹塑性分析中,应合理考虑填充墙的影响。本章首先对砌体填充墙的抗震性能及填充墙的数值模型进行介绍,并着重介绍了基于等效斜压杆的填充墙宏观模型的参数计算方法,最后采用PERFORM-3D[3,4]对一单跨框架填充墙结构的低周往复加载试验进行模拟,讲解PERORM-3D中采用等效斜压杆填充墙模型进行框架填充墙模拟的基本步骤与参数设置方法。In traditional structural analysis, infilled wall is usually considered as non-structural element, and its effect to structure performance was only considered by applying equivalent external load to the main structure and reducing the structure period, the contribution of infilled wall to the structural nonlinear behaviour was not considered directly. Relevant studies have shown that infilled wall has significant influence on both linear and nonlinear structural performance. Therefore, infilled wall should be reasonably considered in structural elasto-plastic analysis. In this chapter, the seismic performance and numerical model of masonry infilled wall was firstly introduced, and the parameters calculation method of the macroscopic infilled wall model based on equivalent diagonal strut theory was explained in detail. After that, a PERFORM-3D simulation of low-cyclic reversed load test of a single span infilled frame structure was conducted by step by step, to explain the fundamental modelling process and parameter definition method of the equivalent diagonal strut infilled wall model.

[书]PERFORM-3D原理与实例 – 第4章 -塑性铰模型

集中塑性铰模型是梁、柱等杆系构件模拟中常用的一种模型。PERFORM-3D[1,2]中,塑性铰是一个截面组件(Component),通过将其与其他组件进行组装得到框架复合组件,用于模拟模拟梁、柱构件的非线性行为。PERFORM-3D包含两类塑性铰组件:弯矩型塑性铰(M铰)和弯矩-轴力相关型塑性铰(P-M-M铰),前者一般用来模拟截面轴力可以忽略的情况,比如梁端非线性行为,后者用来模拟截面轴力-弯矩相互作用的情况,比如柱端非线性行为。根据变形指标的不同,上述每种塑性铰又可以进一步分为转角型塑性铰(Rotation Type)和曲率型塑性铰(Curvature Type),前者用转角作为塑性铰变形的度量,后者用曲率作为塑性铰变形的度量。

[论文][Paper]Deformation Limits of L-Section RC Shear Walls (L形RC剪力墙的变形指标)

In order to establish the relation between damage state and member deformation of the L-section RC shear wall, 216 FE models designed to meet the requirements of the Chinese codes were set up. The analysis fully considers the variation of parameters including axial load ratio and shear span ratio etc. According to the results, criteria of classifying failure modes of L-section RC shear walls are proposed. Failure modes are determined by shear-span ratio, moment-shear ratio and end columns’ reinforcement ratio. Deformation limits corresponding to respective performance levels are put forward. Fitted formulas of calculating the limits are also presented. It is shown that the categorization criteria are reliably accurate in predicting failure modes. Deformation limits of a given L-section RC shear wall could be determined via axial load ratio and moment-shear ratio. The fitted formulas possess a satisfactory correlation with numerical results.

Engineering strain and logarithmic strain (工程应变与对数应变资料整理)

整理对数应变和工程应变的知识。从以上关系可以看出,真实应力比名义应力大,对数应变比名义应变大,当应变比较大时,两者差异会很大。另外,对数应变还具有可比性,可加性,这些都是名义应变所不具有的。以利用上述关系,可将名义应力应变关系转换为真实应力应变关系。

Torsion analysis by thermal analogy with Abaqus (Abaqus热比拟扭转应力分析)

稳态热传导的控制方程与经典扭转理论的控制方程具有相似性。我们可以通过比拟,在通用有限元软件中利用稳态热传导分析的功能进行扭转问题的分析。本文结合Abaqus软件,通过一个实例说明这个比拟的具体过程。(The steady heat conduction problem and the classic torsion theory have analogy in their control partial differential equations. We can conduct a torsional analysis making use of the steady analysis fuction in general finite element program. This post gives an example on how to do torsion analysis as thermal analogy with Abaqus.)

Torsion analysis by thermal analogy with ANSYS (ANSYS热比拟扭转应力分析)

稳态热传导控制方程与扭转控制方程具有相似性。利用ANSYS中的稳态热传导分析功能通过比拟的方法进行截面的扭转应力分析。The steady heat conduction problem and the classic torsion theory have analogy in their control partial differential equations. We can conduct a torsional analysis making use of the steady analysis fuction in general finite element program.This post gives an example on how to do torsion analysis as thermal analogy with ANSYS.

Analysis of a Euler–Bernoulli beam with ANSYS [ANSYS 欧拉-伯努利梁分析]

欧拉伯-努利梁理论(Euler–Bernoulli beam)又称为工程梁理论(Engineering beam theory)或者经典梁理论(Classical beam theory)。欧拉梁不考虑剪切变形,与铁木辛柯梁(Timoshenko beam)相对。前面一篇博文《Analysis of a Euler–Bernoulli beam with Abaqus [Abaqus欧拉-伯努利梁分析]》复习了Abaqus中利用欧拉梁单元B23和B33单元进行悬臂梁的模拟,本文接着看看在 ANSYS APDL 中如何利用欧拉梁单元进行同样的分析。

Analysis of a Euler–Bernoulli beam with Abaqus [Abaqus欧拉-伯努利梁分析]

复习有限元知识,利用 Abaqus 进行欧拉伯努利梁单元的分析。欧拉伯努利梁理论(Euler–Bernoulli beam)又称为工程梁理论(Engineering beam theory)或者经典梁理论(Classical beam theory)。欧拉梁不考虑剪切变形,与铁木辛柯梁(Timoshenko beam)相对。Abaqus中的B23和B33单元为欧拉梁单元。

[Tool][软件][动力学]NSDOF v2016: A Tool for Nonlinear Dynamic Analysis of SDOF System (NSDOF: 单自由度系统动力非线性分析工具)

SDOF是一个基于微软的windows窗口程序,用于单自由度结构的动力非线性分析。结构可是弹性也可以是弹塑性。动力荷载可以是施加在结构基座的地震加速度,也可以是施加在结构顶部的动力荷载。程序使用逐步积分法求解增量非线性运动方程。SDOF is a Microsoft Windows based application for the dynamic analysis of single degree of freedom structural systems. The structure may be modeled as elastic, elastic-plastic. The dynamic loading may be input as an earthquake accelerogram acting at the base of the structure, or as a dynamic force applied at the roof of the structure. The program uses a step-by-step method to solve the incrementally nonlinear equations of motion.

[下载][Tool][软件] OSMatTest: OpenSees Material Test [OpenSees单轴材料测试工具]

[App]OpenSees Material Test.A small program to test the uniaxial materials in OpenSees.OpenSees Material Test将OpenSees ( Open System for Earthquake Engineering Simulation )中常用的单轴本构关系(钢及混凝土本构)提取出来,通过自行设计的界面进行测试,为今后更加深入的研究奠定基础。

OpenSees Concrete04 Material Test

Concrete04受压部分的包络线采用Popovics (1973) 提出的单调荷载下的应力—应变关系,并根据Karsan-Jirsa加卸载准则确定其加卸载刚度(线性);受拉部分的包络线由线性上升段和指数下降段组成,其加卸载与再加载刚度取其与原点的割线刚度。(Concrete is a uniaxial Popovics concrete material object with degraded linear unloading/reloading stiffness according to the work of Karsan-Jirsa and tensile strength with exponential decay.)

OpenSees Concrete02 Material Test

OpenSees Concrete02 Material Test.Concrete02与Concrete01相比,考虑了混凝土的受拉力学性能(线性)。在受压方面,与Concrete01相同的是,考虑了混凝土随着残余应变的增大,加、卸载的刚度发生退化;不同的是,Concrete02在同一卸载过程,卸载的刚度也在发生退化。