公共建筑结构设计分析

本工程采用框架剪力墙结构体系,结构设计上通过核心筒作为竖向落地支承,并通过空腹桁架+单层空间网壳的结构形式,钢结构部分主要由屋盖结构体系与球形结构体系两大体系组成,通过建立有限元模型分析多遇地震及罕遇地震下结构的受力模式以及变形。研究结果表明:采用框架剪力墙结构以及通过空腹桁架+单层空间网壳的结构形式在满足规范下,最大化实现建筑的功能要求。

淮河模型试验大厅大跨度钢结构分析计算方法

淮河模型试验大厅工程为大跨度异型空间管桁架结构,下部支撑结构为矩形钢管混凝土排架结构。通过对淮河模型试验大厅工程的结构分析,介绍了该结构的结构方案,荷载取值,并分别采用SAP2000和Midas对上部屋盖及下部矩形钢管混凝土排架结构进行了整体模态分析。为了考察该结构的薄弱部位,并进一步对该结构做了三方向的推覆分析。计算表明,结构受力合理,能满足规范要求。

商业住宅楼剪力墙框架结构设计要点探究

文章以某商业住宅楼为例,针对住宅楼剪力墙框架结构设计重点进行了深入地分析,着重从结构设计、基础设计、结构弹性分析等方面进行了论述,为今后建筑楼剪力墙框架设计提供理论参考。

某幼儿园消能减震设计分析

本工程基于多遇、罕遇地震作用下原结构与消能减震结构地震响应的对比分析表明,结构采用消能减震设计之后,较好地改善了原结构薄弱层的抗震性能,附加阻尼器减震设计后主体结构部分的抗震安全性大大提高,在罕遇地震作用下呈现“强柱弱梁”的塑性铰发展机制,且在带阻尼器-支撑立面上主体结构部分的塑性发展程度也比较小,这表明主体结构在罕遇地震作用下的损伤状况能够得到有效控制和改善,从而使得整体结构具有良好的抗震性能,更有利于实现“大震不倒”的设防目标。

广州珠江新城高尚住宅结构设计

本工程为76～145 m高,地下2层,地上23～45层的住宅小区。工程地下室采用现浇钢筋混凝土框架结构,地上住宅部分采用现浇剪力墙结构。工程设计时,采用SATWE在多遇地震情况下对工程的强度、刚度、整体稳定性进行了计算分析,并进行了弹性时程分析。对超高层住宅设计具有一定的参考作用。

涪陵商业步行街高位转换结构设计

采用PMCAD-SATWE和从MIDAS BUILDING两种有限元软件对重庆涪陵商业步行街项目进行了反应谱分析,弹性时程分析及应力分析等,并根据计算结果确定了相应的加强措施,以确保该超限高层结构安全。

Application of laminated vierendeel truss in high-position transfer story structure

To meet the demands for large space and flexible compartmentation ofbuildings, laminated vierendeel trasses are adopted in high-position transfer story structures.First the bearing characteristics are analyzed, in which reasonable stiffness ratio of the upperchord, middle chord, and lower chord is derived. Then combined with an actual engineering model (1:8similar ratio), the static loading and pseudo-dynamic tests of two models for laminated vierendeeltrass used in transfer story structures are conducted, in which one model adopts reinforcedconcrete, and the other adopts prestressed concrete and shape steel concrete. Seismic behaviors areanalyzed, including inter-story displacement, base shear-displacement skeleton curves, andequivalent viscosity-damping curves. A program is programmed to carry out the elasto-plastic dynamicanalysis, and displacement time-history curves of the two models are derived. The test and analysisresults show that the laminated vierendeel trass with prestressed concrete and shape steel concretehas excellent seismic behaviors. It can solve the disadvantages of laminated vierendeel trussesused in transfer story structures. Finally, some design suggestions are put forward, which can bereferenced by similar engineering.

Structural Analogy for Dynamic Analysis of Liquid Sloshing

The analogy between the wave equation of liquid and the Navier equations of structural elasticity is examined in detail. By introducing appropriate parameters, the structural counterpart of the liquid sloshing model can be easily built. Therefore, the dynamic analysis of liquid sloshing can be reduced to that of structural elasticity, and the existing FEM structural analysis computer programs can be applied to liquid sloshing analysis without any modification. The present method also reveals the internal relationship between liquid sloshing and structural vibration. The effectiveness and reliability of the method is illustrated by the numerical example.

谈SAP2000在空间构架式动力机器基础中的应用

结合SAP2000程序的特点对已建成使用的某钢厂电动鼓风机基础进行SAP2000程序计算,并对其计算结果进行分析、评价,以便在动力基础设计时更好地利用SAP2000程序。

Hydroelastic Analysis of a Very Large Floating Structure Edged with a Pair of Submerged Horizontal Plates

This paper is concerned with the hydroelastic problem of a very large pontoon-type floating structure(VLFS) edged with a pair of submerged horizontal plates, which is a combination of perforated and non-perforated plates attached to the for-end and back-end of the VLFS. For the hydroelastic analysis, the fluid is assumed to be ideal and its motion is irrotational so that a velocity potential exists. The VLFS is modeled as an elastic plate according to the classical thin plate theory. The fluid-structure interaction problem is separated into conventional hydrodynamics and structure dynamics by using modal expansion method in the frequency-domain. It involves, firstly, the deflection of the VLFS, which is expressed by a superposition of modal functions and corresponding modal amplitudes. Then the boundary element method is used to solve the integral equations of diffraction and radiation on the body surface for the velocity potential, whereas the vibration equation is solved by the Galerkin's method for modal amplitudes, and then the deflection is obtained by the sum of multiplying modal functions with modal amplitudes. This study examines the effects of the width and location of the non-perforated horizontal plates on the hydroelastic response of the VLFS, then the performance of perforated plates is investigated to reduce the motion near the fore-end of the VLFS. Considering the advantages and disadvantages of submerged plates without and with cylindrical holes, we propose a simple anti-motion device, which is a combination of a pair of perforated and non-perforated plates attached to the for-end and back-end of the VLFS. The effectiveness of this device in reducing the deformation and bending moment of the VLFS has been confirmed, and is compared with the results in cases without and with the submerged horizontal plates by the analysis in this paper.

Equivalent Bar Conceptions for Computer Analysis of Pantographic Foldable Structures

An equivalent bar conception is firstly developed for the computer analysis of pantographic foldable structures. The uniplet of two three node beam elements is assumed as a six bar assembly with respect to least norm least square solution for the elastic strain energy equality. The equilibrium equation is developed for the equivalent models, and the internal forces formulated sequently for backup calculation. This procedure is proved practical for some engineering, and some interesting concepts proposed. Finally, three numerical tests are presented.

Stability and reinforcement analysis of rock slope based on elasto-plastic finite element method

The rigid body limit equilibrium method(RBLEM) and finite element method(FEM) are two widely used approaches for rock slope's stability analysis currently. RBLEM introduced plethoric assumptions; while traditional FEM relied on artificial factors when determining factor of safety(FOS) and sliding surfaces. Based on the definition of structure instability that an elasto-plastic structure is not stable if it is unable to satisfy simultaneously equilibrium condition, kinematical admissibility and constitutive equations under given external loads, deformation reinforcement theory(DRT) is developed. With this theory, plastic complementary energy(PCE) can be used to evaluate the overall stability of rock slope, and the unbalanced force beyond the yield surface could be the identification of local failure. Compared with traditional slope stability analysis approaches, the PCE norm curve to strength reduced factor is introduced and the unbalanced force is applied to the determination of key sliding surfaces and required reinforcement. Typical and important issues in rock slope stability are tested in TFINE(a three-dimensional nonlinear finite element program), which is further applied to several representatives of high rock slope's stability evaluation and reinforcement engineering practice in southwest of China.

Using Thermoelastic Stress Analysis to Detect Damaged and Hot Spot Areas in Structural Components

This paper discusses the suitability of using TSA （thermoelastic stress analysis） as an advanced tool to detect damaged areas and highly stressed （hot spot） areas in structural components. Such components can be, for example, parts of large structural panels built of welded metallic or composite materials. Besides detecting hot spot areas, it is expected that stresses in these areas can be suitably quantified and processed in order to predict crack initiation and propagation due to in-service loads. The paper starts with references to selected review and application articles on the subject. Two simple laboratory experiments are presented which illustrate the quality of the results that can be achieved using TSA. In the first experiment, a stainless steel T-joint designed to model a welded structural component is analysed. The T-joint had a machine-notched crack-like flaw close to the component＇s weld toe. The qualitative and quantitative experimental results determined along four specified areas of the T-joint model showed that TSA can indeed be used as a tool to detect loaded cracks and hot spots in large metallic structures, and that stresses can be accurately evaluated. In the second experiment, a prismatic bar made of CFRE （carbon fibre-reinforced-epoxy） was tested to locate three subsurface areas of damage introduced beforehand into the component. Two of these inside damaged areas were detected to be 3.1 mm and 7.1 mm from the observed surface. The positive results achieved with the two lab experiments, along with a review of the selected research publications, indicate that TSA application can be extended to the real-world field of structural components. Topics to be addressed in this research field should have to do with components that work under random or quasi-cyclic service loading, problems where adiabatic conditions do not prevail, and reduction of the cost of infra-red cameras.

Thermoelastic Stress Analysis of a Finite Structure Containing an Asymmetrical-Oriented, Arbitrarily-Shaped Hole

Stresses, particularly those at geometric discontinuities, influence the structural integrity of engineering components. Motivated by the prevalence of complicated-shaped perforated components, the objective of this paper is to demonstrate the ability to stress analyze loaded finite members containing asymmetrical, irregularly-shaped cutouts. Recognizing the difficulties in obtaining purely theoretical or numerical solutions for these situations, the paper presents an expeditious means of experimentally stress analyzing such structures. Processing the load-induced temperature information with a series representation of a stress function provides the independent stress components reliably full-field, including on the edge of a hole. The stresses satisfy equilibrium and strains satisfy compatibility. In addition to being able to stress analyze complicated shapes using real, rather than complex variables, the technique is significant in which it smooths the recorded thermal information, is widely applicable, and requires neither differentiating the measured data nor knowing the elastic properties or external boundary conditions. The latter is extremely important since the external loading is often unknown in practice. That the approach provides the independent stresses is also significant since fatigue analyses and strength criteria typically necessitate knowing the individual components of stress. Present results are supported by those from a finite element analysis, strain gage measurements and load equilibrium.

Deployment simulation of cable-strut structures considering cable sliding

The influence of cable sliding on the deployment of foldable cable-strut structures was studied in this paper. In order to develop an effective program for the cable sliding program, two-node cable element based on the analytical solution of elastic cate- nary was studied. Then the cable sliding stiffness was defined as the ratio of the variation of the cable force to the variation of the cable length. To validate the proposed numerical method, analyses of two examples given in references were carried out. The results show that the method given in this paper is accurate and effective, which can be used to model the cable sliding in cable structures. Finally, the deployment process of a foldable cable-strut structure, which is composed of four-bar linkages and cables, was discussed. It can be found that the effect of cable sliding on the behavior of cable-strut structures is significant. The length changes of active cables are smaller when the cable sliding is considered. Moreover, the nodal coordinate changes also become faster when the numerical model is with cable sliding.

Second-order two-scale method for bending behavior analysis of composite plate with 3-D periodic configuration and its approximation

This paper considers the bending behaviors of composite plate with 3-D periodic configuration.A second-order two-scale(SOTS)computational method is designed by means of construction way.First,by 3-D elastic composite plate model,the cell functions which are defined on the reference cell are constructed.Then the effective homogenization parameters of composites are calculated,and the homogenized plate problem on original domain is defined.Based on the Reissner-Mindlin deformation pattern,the homogenization solution is obtained.And then the SOTS’s approximate solution is obtained by the cell functions and the homogenization solution.Second,the approximation of the SOTS’s solution in energy norm is analyzed and the residual of SOTS’s solution for 3-D original in the pointwise sense is investigated.Finally,the procedure of SOTS’s method is given.A set of numerical results are demonstrated for predicting the effective parameters and the displacement and strains of composite plate.It shows that SOTS’s method can capture the 3-D local behaviors caused by3-D micro-structures well.

Aeroelastic stability analysis of heated panel with aerodynamic loading on both surfaces

Focusing on the aeroelastic stability of thin panel structure of airframe component such as engine nozzle of high-speed flight vehicles,a nonlinear aeroelastic model for a two-dimensional heated panel exposing both surfaces to the airflow with different aerodynamic pressures is established.The von Karman large deflection plate theory and the first-order piston theory are used in the formulation of aeroelastic motion.The critical conditions for aeroelastic stability and the stability boundaries are obtained using theoretical analysis and numerical computations,respectively.The results show that the panel is more prone to become unstable when its two surfaces are subject to aerodynamic loading simultaneously;only if the sum of the aerodynamic pressures on both surfaces of the panel satisfies flutter stability condition,can the panel be likely aeroelastically stable;compared with the general panel flutter problem that only one surface is exposed to the airflows,the present condition makes the panel become aeroelastically unstable at relatively small flight aerodynamic pressure.

Pushover analysis of underground structures:Method and application

Pushover analysis is common because of its conceptual simplicity and computational attractiveness in computing seismic demand.Considering that traditional pushover analysis is restricted in underground structures due to the stark differences in the seismic response characteristics of surface structures,this paper proposes a pushover analysis method for underground structures and its application in seismic damage assessment.First,three types of force distribution are presented based on ground response analysis.Next,the target displacements and analysis models are established according to force-based and performance-based design.Then,the pushover analysis procedure for underground structures is described.Next,the applicability of pushover analysis to underground structures is verified by comparing the responses of a Chongwenmen subway station determined by the proposed procedure and by nonlinear response history analysis.In addition,two other points are made:that the inverted triangular distribution of effective earthquake acceleration is more practical than the other two distributions,and that performance-based design is more effective than force-based design.Finally,a cyclic reversal loading pattern based on one cycle of reversal loads as an earthquake event is presented and applied to the seismic damage assessment of underground structures.The results show that the proposed pushover analysis can be effectively applied to the seismic design and damage assessment of underground structures.

Dynamic Response of Warship Structure under Air Non-contact Explosion

The ship hull is simplified as a free beam with varying sections. Based on hydroelasticity and explosion mechanics theory,mechanical model and kinetic equation for hull girder vibration under non-contact explosion are established. The equation is solved by Wilson-θ algorithm. On the basis of the above principles,a structure kinetics analysis program is compiled. The dynamic response of supposed warship under air explosion is calculated conveniently and quickly. Under the explosion condition designed in the paper,the positive pressure period of non-contact explosion wave is much less than the natural periods of the first four modes of hull girder and the resonance of ship girder overall vibration can be avoided. The ratio of midship maximum moment to ultimate bearing strength under non-contact explosion accelerates with the increment of impact factor.