The hybrid simulation (HS) testing method combines physical test and numerical simulation, and provides a viable alternative to evaluate the structural seismic performance. Most studies focused on the accuracy, stability and reliability of the HS method in the small-scale tests. It is a challenge to evaluate the seismic performance of a twelve-story pre-cast reinforced concrete shear-wall structure using this HS method which takes the full-scale bottom three-story structural model as the physical substructure and the elastic non-linear model as the numerical substructure. This paper employs an equivalent force control (EFC) method with implicit integration algorithm to deal with the numerical integration of the equation of motion (EOM) and the control of the loading device. Because of the arrangement of the test model, an elastic non-linear numerical model is used to simulate the numerical substructure. And non-subdivision strategy for the displacement inflection point of numerical substructure is used to easily realize the simulation of the numerical substructure and thus reduce the measured error. The parameters of the EFC method are calculated basing on analytical and numerical studies and used to the actual full-scale HS test. Finally, the accuracy and feasibility of the EFC-based HS method is verified experimentally through the substructure HS tests of the pre-cast reinforced concrete shear-wall structure model. And the testing results of the descending stage can be conveniently obtained from the EFC-based HS method.

Utilizing the powerful matrix calculating function from Matlab and the open-source characteristics from OpenSEES,this paper proposes a substructure testing system based on Matlab-OpenSEES by adopting mixed programming.It introduces three basic components,which are the Matlab module,the OpenSEES numerical substructure simulation module and the interface function between Matlab and OpenSEES,and the principle of the proposed substructure system.The Matlab module is used to realize the function of solving motion equation,the loading control,and data acquisition of experimental substructure.The OpenSEES numerical substructure simulation module,which is a submodule called by Matlab module,is used to realize the numerical simulation analysis of numerical substructure.The interface is used to realize the data transmission between Matlab and OpenSEES by the text or Socket communication variables.The proposed system can be programmed on an external computer connected with the hardware I/O channel of the MTS electro-hydraulic servo control system through the data acquisition card.In this way,the system can not only avoid the complex underlying programming technology of the electro-hydraulic servo control system,but also reduce the requirement of system itself and finally reduce the test difficulty and cost.The test results of three large-scale structure test models verify the feasibility of the proposed substructure testing system.

采用力-位移混合控制方法,提出了考虑倾覆力矩的子结构混合模拟试验方法.采用ANSYS有限元软件,进行了不同的加载分布方式、试验子结构刚度发生变化、不同梁柱线刚度比以及不同结构层数等情况下的数值模拟,初步验证所提方法的可行性.以6层钢框架模型为例,实现了考虑倾覆力矩情况下的子结构混合模拟试验.试验结果表明:不考虑界面倾覆力矩,将改变结构在地震作用下的内力分布和破坏模式,不能真实地反映结构在地震作用下的力学性能.

This paper proposed the hybrid simulation test method based on the similar theory for the scale model to reduce the cost and improve the efficiency of the experiment. The proposed method deduces theoretically the similarity conditions of both displacement and force under the identical material between the model and the prototype. The obtained similarity conditions are only used for the physical substructure. The parameters of both the motion equation and the numerical substructure are not changed. So it is easy to use the proposed method for the hybrid simulation testing method. Using the mixed programming method of MATLAB and OpenSEES, this paper realizes both the tradition substructure test method for the scale model, including shear model, bending?shear model and bending model, and the distribution substructure test method for the scale model. Compared with the numerical simulation results of the corresponding full scale model, the proposed method is validated.

实验教学是培养学生工程实践能力和创新意识的一种重要手段,然而作为土木工程专业的一门重要专业基础课,《结构力学》是没有实验内容的,这严重制约了教学实践课程的深入开展,同时影响了学生对理论内容的理解和掌握.本文详细介绍了自主研发的一套积木式实验结构力学平台.该平台可方便地安装各种测试仪器仪表、加载装置,实现了平面结构中常用的各种约束装置以及防平面外变形限位装置,基本满足学生进行自主、自组、创新、开放实验的要求,为实验结构力学的发展和推广提供了良好的基础设施.

Based on the feasibility and reliability of a forward analytical model updating method with uniform design having been proven, this paper studies the effectiveness of the method in the condition that structural measured information is uncertain and incomplete. By taking the experimental data of a steel truss as an example, this paper studies the method of experimental data processing, the determination of structural model with unknown parameters, the interval estimation of identification results and stepwise uniform design considered the correlation among identification parameters. The results show that the errors between the numerical results computed by the updated model and the experimental data are acceptable, which means the method in this paper is feasible and reliable. In the end, based on our experiences and lessons, we summarize a model updating method for complex structures using stepwise uniform design schemes considered the primary and secondary factors, and expound its computational steps.

This paper proposed multiple substructural interface simulation methods, which based on shear framework model. By applying the OpenSEES finite element software to get the error of numerical simulation, it is shown that conventional solutions include two methods, one ignores the overturning moment and another considers the overturning moment, have relatively large error in not only the macro-displacement and hysteresis loop but also the internal force on the condition of shear structure. The paper proposed three methods taking the overturning moment of the interface into account, which are promoted significantly compared with the conventional solution. The method in consideration of all factors on the interface, the method one based on inflection point and the method two based on inflection point own roughly equal errors. The method two based on inflection point use prediction of interface axial deformation strategy, could effectively avoid the difficulty of loading existing in the process of moment simulation of the method in consideration of all factors on the interface. It also prevents the difficulty of testing resulting from the axial deformation in the method one based on inflection point. So the method two based on inflection point can effectively realize the simulation of the structural interface.

SUMMARYThe effectiveness of equivalent force control (EFC) method has been experimentally validated through hybrid tests with simple specimens. In this paper, the EFC method is applied for the MDOF pseudo‐dynamic substructure tests in which a three‐storey frame‐supported reinforced concrete masonry shear wall with full scale is chosen as physical substructure. The effects of equivalent force controller parameters on the response performance are studied. Analytical expressions for the controller parameter ranges are derived to avoid response overshooting or oscillation and are verified by numerical simulation. The controller parameters are determined based on analytical and numerical studies and used in the actual full‐scale pseudo‐dynamic test. The test results show good tracking performance of EFC, which indicates a successful test. Copyright © 2013 John Wiley & Sons, Ltd.

基于经过试验验证过的考虑截面翘曲影响的纤维单元模型,该文考虑工程中剪力墙的可能高宽比范围、配筋率、轴压比、砌体抗压强度值等主要因素,用均匀设计法安排一字型配筋砌块砌体剪力墙悬臂梁模型数值模拟试验方案,进行拟静力试验数值模拟分析.结合实际试验结果,回归分析得到该类墙片恢复力特征参数与所考虑因素之间的经验公式,为一字型配筋砌块砌体剪力墙为抗侧力结构的高层结构弹塑性分析奠定了基础.

In order to effectively update structural models by the neural network method based on uniform design, this paper takes beam structures as objects to study three problems that are the completeness of uniform design sampling scheme, the method of extending the uniform design sampling scheme and how to choose excellent neural network samples. The difference between the uniform design sampling scheme and the complete sampling scheme is analyzed. An idea of factor rearranging is proposed to extend the uniform design sampling scheme. A fuzzy analytical hierarchy process is used to evaluate and choose excellent neural network samples. The results show that the uniform design sampling scheme is an approximate complete sampling scheme and the idea of factor rearranging can extend the uniform design sampling scheme effectively. In the process of model updating of large complicated structures, the uniform design sampling scheme should be extended by the way of factor rearranging to improve the accuracy of model updating and physical variables with definite physical significance should be used as the samples of neural networks.

Be based on a full-scale three-storey pre-cast reinforced concrete shear wall substructure test model, this paper conducts the numerical simulation and experimental study on the equivalent force control of the complex model which includes the multi-degree of freedom of a physical substructure and a elastic non-linear numerical substructure. The test results show that the equivalent force control method for the complex model is feasible and can obtain the descent stage test data.

Control effect of isolation control system with energy transducer in structural seismic response reduction was researched from the aspects of energy.The system can reduce structural vibration because of the energy transition,and the energy can be used for further structural control.The relation of transducer control force and isolator stiffness ratio was studied and the formula of control force was suggested The influence of different combination of energy transition device and isolator design on transition efficiency was explored.and the design process of the system was given.Based on the process presented,the transition efficiency can achieve 70%,the control effect can be over 65%.

Based on the artificial neural network, the parameters of a steel truss are identified. And the finite element model of truss is corrected. In order to improve the efficiency of model updating by artificial neural networks, the momentum is introduced into the back propagation algorithm. Based on the theory of probability and mathematical statistics, the expectation confidence interval of the measured deflections and strains is obtained. In this way, the samples to train the neural network are optimized. The numerical results show that the back propagation neural network proposed on this paper is able to correct the finite element model of the truss effectively.

In order to evaluate the identification precision and the computational efficiency of identification indices on damage detection and provide a reasonable basis to choose identification indices for deeply developing structural damage identification, a fuzzy analytical hierarchy process is used to comprehensive analyse and assess nine kinds of identification indices. By establishing the mathematical relationship between the precedence relation matrix and the fuzzy judgement matrix, the consistency of the judgement matrix in analytical hierarchy process is effectively improved. Using above methods and based on three evaluation standards that include mean error, network scale and measuring difficulty, a fuzzy hierarchy to assess identification indices is set up. On the basis of the fuzzy judgement matrix, the performance of nine kinds of identification indices is ranked. Empirical results show that deflection, first modal shape and fundamental frequency are more suitable for identification indices than other indices. And a fuzzy judgement matrix can be established only using the relative relationship between identification indices in the fuzzy analytical hierarchy process. Thus, the fuzzy analytical hierarchy process can be convenient extended to evaluate other identification indices and effectively improve the identification precision and the computational efficiency on damage detection.

In order to figure out the cable flexural rigidity influence on suspension bridges,a contrast model experiment is made:a chain cable model with no flexural rigidity and a wire cable model with some flexural rigidity.And then,four finite element models of a same long-span suspension bridge with different cable element are set up to be analyzed.Both experimental and numerical simulation results show that,with the increase of the span and the decrease of sag-span ratio,the influence of the cable flexural rigidity is significant.The difference of nodes displacement reaches more than 10 cm in construction analysis,which will bring some trouble to the construction.And the difference of the maximum section edge normal stress may reach 15%,which may have an adverse impact onto the bridge.Therefore,considering the cable flexural rigidity is necessary on some analysis of suspension bridges.

In order to obtain a deeper understanding of the behavior of the structure under high wind load, this paper conducted an experimental study on a full-scale L-shaped single story light frame wood house under the uniform lateral load simulated using a gasbag. The investigation involved the performance of light frame wood structure after it experienced the repeated cyclic lateral wind load as well as the performance of the structure under the ultimate lateral load. Then, the study verified that light frame wood structure can resist repeated cyclic wind loads without observable degradation in stiffness during the anticipated serve life, and recommended shear wall percent drift restriction for lateral wind load design of wood structure in serviceability limit states is 1/400 drift, and in ultimate limit states is 1/80 drift. The conclusions of this paper can be benefit for the engineering practice of the light frame wood structures in high wind load regions.

在现有结构力学教材中,关于虚功原理的表述大体上可以分为4大类:虚功原理是一充分必要性命题;虚功原理是一充分必要性命题但只证明必要性部分;虚功原理仅仅是必要性命题,但它有2种"应用"——虚位移原理和虚力原理;虚功原理仅仅是必要性命题,它和虚位移原理、虚力原理是有异同的.即使是最近出版的"十一五"规划教材中,也还存在虚功原理是一充分必要性命题的提法.为此,再次给出原理的正确阐述和证明,指出需要对虚功原理和虚位移原理加以区分,阐明它们之间的异同.

14 wood shear walls and 2 diaphragms were tested.The specimens were made according to common light frame wood engineering practices in China.All the specimens were tested under monotonic load protocol.Finite element analysis was executed to extend study of the shear walls.Furthermore,a method for calculating lateral stiffness based on displacements was provided.The studies verified that the lateral stiffness and strengths of shear walls were proportion to the lengths.The lateral stiffness and strengths of perforated and gypsum board sheathed shear walls were studied,and the methods to improve stiffness and strengths of the walls were compared.The stiffness and strengths of unblocking floor diaphragm were studied.It is found that sheathings of diaphragm transfer shear loads and most moment loads,while the maximum slips of sheathing-to-framing joints of diaphragm were found in unblocking edges of sheathings in corner areas.Some other useful conclusions were also obtained in the study.