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Acta Mechanica Solida Sinica 2006年第3期19卷 231-240页

作者： Pan Jin Wang De-yu State Key Lab of Ocean Engineering School of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University Shanghai 200030 China

In this paper, adaptive genetic algorithm （AGA） is applied to topology optimization of truss structure with frequency domain excitations. The optimization constraints include fundamental frequency, displacement responses under force excitations and acceleration responses under foundation acceleration excitations. The roulette wheel selection operator, adaptive crossover and mutation operators are used as genetic operators. Some heuristic strategies are put forward to direct the deletion of the extra bars and nodes on truss structures. Three examples demonstrate that the proposed method can yield the optimum structure form and the lightest weight of the given ground structure while satisfying dynamic response constraints.

关键词： fundamental frequency dynamic response adaptive genetic algorithm topology optimization truss structure

Fused empirical mode decomposition and wavelets for locating combined damage in a truss-type structure through vibration analysis

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第9期14卷 615-630页

作者： Arturo GARCIA-PEREZ Juan P. AMEZQUITA-SANCHEZ Aurelio DOMINGUEZ-GONZALEZ Ramin SEDAGHATI Roque OSORNIO-RIOS Rene J. ROMERO-TRONCOSO HSPdigital-CA Telematica-Procesamiento Digital de Se ales DICIS Universidad de Guanajuato Carr. Salamanca-Valle km 3.5+1.8 Palo Blanco 36885 Salamanca Gto. Mexico HSPdigital CA Mecatronica Facultad de Ingeniería Campus San Juan del Río Universidad Autonoma de Queretaro Moctezuma 249 Col. San Cayetano 76807 San Juan del Río Qro. Mexico Department of Mechanical and Industrial Engineering Concordia University1455 de Maisonneuve Boulevard West Montreal QC H3G 1M8 Canada

Structural health monitoring (SHM) is a relevant topic for civil systems and involves the monitoring, data processing and interpretation to evaluate the condition of a structure, in order to detect damage. In real structures, two or more sites or types of damage can be present at the same time. It has been shown that one kind of damaged condition can interfere with the detection of another kind of damage, leading to an incorrect assessment about the structure condition. Identifying combined damage on structures still represents a challenge for condition monitoring, because the reliable identification of a combined damaged condition is a difficult task. Thus, this work presents a fusion of methodologies, where a single wavelet-packet and the empirical mode decomposition (EMD) method are combined with artificial neural networks (ANNs) for the automated and online identification-location of single or multiple-combined damage in a scaled model of a five-bay truss-type structure. Results showed that the proposed methodology is very efficient and reliable for identifying and locating the three kinds of damage, as well as their combinations. Therefore, this methodology could be applied to detection-location of damage in real truss-type structures, which would help to improve the characteristics and life span of real structures.

关键词： truss structure Vibration Spectral analysis Wavelet packet transform Empirical mode decomposition Artificialneural network (ANN)

VIBRATION CONTROL OF A SPACE truss structure WITH A PIEZOELECTRIC ACTIVE MEMBER

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Transactions of Nanjing University of Aeronautics and Astronautics 1997年第2期14卷 177-185页

作者：李俊宝张令弥西安交通大学机械结构强度与振动国家重点实验室西安710049 南京航空航天大学振动工程研究所南京210016

Active vibration control is an effective way of increasing robustness of the design to meet the stringent accuracy requirements for space structures. This paper presents the results of active damping realized by a piezoelectric active member to control the vibration of a four-bay four-longern aluminum truss structure with cantilever boundary. The active member, which utilizes a piezoelectric actuating unit and an integrated load cell, is designed for vibration control of the space truss structures. Active damping control is realized using direct velocity feedback around the active member. The placement of the active member as one of the most important factor of affecting the control system performance, is also investigated by modal dissipation energy ratio as indicator. The active damping effectiveness is evaluated by comparing the closed-loop response with the open loop response.

关键词： vibration trusses active damping control piezoelectric active member optimal placement truss structure

An improved equivalent beam model of large periodic beam-like space truss structures

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Chinese Journal of Aeronautics 2023年第12期36卷 297-308页

作者： Dongfang ZHU Xiaoxuan YAN Jun SUN Fucheng LIU Dongxing CAO Shanghai Aerospace Control Technology Institute Shanghai 201109China Shanghai Key Laboratory of Aerospace Intelligent Control Technology Shanghai 201109China Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing 100124China

Space truss structures are essential components for space-based remote sensing loads with high spatial and temporal *** achieve high-precision vibration control,an accurate and efficient dynamics model is *** addition to the current equivalent beam model(EBM)based on the classical continuum theory,an improved equivalent beam model(IEBM)is proposed that considers the impact of the distinction between trusses and beams on torsional and shear deformations,as well as the impact of shear deformation on flexural *** to the displacement expressions of spatial beams,torsional,shear,and bending correction coefficients are introduced to derive expressions of strain energy and kinetic *** energy equivalence principle is then utilized to calculate the elasticity and inertia matrices,and dynamics equations are established using the finite element ***,an IEBM is constructed by employing the particle swarm optimization approach to determine the correction coefficients with the truss natural frequency as the optimization *** natural vibration characteristics of the structure are estimated for various material *** with the full-scale finite element model,the EBM reaches a maximum error of 80%for a low modulus of elasticity,while the maximum error of the IEBM is less than 2%for any given parameters,indicating its superior accuracy to the EBM.

关键词： Energy equivalence principle Improved equivalent beam model(IEBM) Natural vibration characteristic Particle swarm optimization approach truss structure

DESIGN OPTIMIZATION FOR truss structureS UNDER ELASTO-PLASTIC LOADING CONDITION

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Acta Mechanica Solida Sinica 2006年第3期19卷 264-274页

作者： Liu Tao Deng Zichen Department of Engineering Mechanics Northwestern Polytechnical University Xi＇an 710072 China State Key Laboratory of Structural Analysis of Industrial Equipment Dalian University of Technology Dalian 116024 China

In this paper, a method for the design optimization of elasto-plastic truss structures is proposed based on parametric variational principles （PVPs）. The optimization aims to find the minimum weight/volume solution under the constraints of allowable node displacements. The design optimization is a formulation of mathematical programming with equilibrium constraints （MPECs）. To overcome the numerical difficulties of the complementary constraints in optimization, an iteration process, comprising a quadratic programming （QP） and an updating process, is employed as the optimization method. Furthermore, the elasto-plastic buckling of truss mem- bers is considered as a constraint in design optimization. A combinational optimization strategy is proposed for the displacement constraints and the buckling constraint, which comprises the method mentioned above and an optimal criterion. Three numerical examples are presented to show the validity of the methods proposed.

关键词： parametric variational principles elasto-plasticity truss structure optimization elasto-plasticity buckling

System Reliability Analysis for truss structures Based on Automatic Updated Model

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Computer Modeling in Engineering & Sciences 2023年第3期134卷 2057-2071页

作者： Pengyu Chen Cunbao Zhao He Yao Junliang Li State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering structures Shijiazhuang Tiedao UniversityShijiazhuang050043China

Multiple failure modes tend to be identified in the reliability analysis of a redundant truss *** identification process involves updating the model for identifying the next potential failure *** we intend to update the finite element model automatically in the identification process of failure modes and further perform the system reliability analysis *** study presents a framework that is implemented through the joint simulation of MATLAB and APDL and consists of three parts:reliability index of a single member,identification of dominant failure modes,and system-level reliability analysis for system reliability analysis of truss ***,RSM(response surface method)combines with a constrained optimization model to calculate the reliability indices *** theβ-unzipping method is adopted to identify the dominant failuremodes,and the system function in MATLAB,as well as the EKILL command in APDL,is used to facilitate the automatic update of the finite element model and realize ***,the differential equivalence recursion algorithmis performed to approximate the reliability indices of failuremodes efficiently and ***,the PNET(probabilistic network evaluation technique)is used to calculate the joint failure probability as well as the system reliability *** illustrative examples demonstrate the accuracy and efficiency of the proposed system reliability analysis framework through comparison with corresponding references.

关键词： Multiple failure modes truss structure automatic update system reliability analysis framework

A NEW METHOD FOR STRUCTURAL TOPOLOGICAL OPTIMIZATION BASED ON THE CONCEPT OF INDEPENDENT CONTINUOUS VARIABLES AND SMOOTH MODEL

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Acta Mechanica Sinica 1998年第2期14卷 179-185页

作者：隋允康杨德庆 Department of Mechanics Dalian University of Technology Dalian China 116023

A concept of the independent-continuous topological variable is proposed to establish its corresponding smooth model of structural topological optimization. The method can overcome difficulties that are encountered in conventional models and algorithms for the optimization of the structural topology. Its application to truss topological optimization with stress and displacement constraints is satisfactory, with convergence faster than that of sectional optimizations.

关键词： structural topological optimization smooth model adaptive algorithm truss structure independent-continuous variable filter function

Internal force and deformation matrixes and their applications in load path

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第8期11卷 563-570页

作者： Qi CHEN Xin-jian KOU Yan-meng ZHANG Department of Civil Engineering Shanghai Jiao Tong University Shanghai 200240 China

This paper deals with the internal force and the deformation matrixes, both of which can be used to analyze the topological relationship of a structure. Based on the reciprocal theorem, the relationship between the two matrixes is established, which greatly simplifies the computation of the internal force matrix. According to the characteristics of the internal force matrix, the transfer law of the matrix itself (due to the removal of components) is established based on the principle of linear superposition. With the relation of the two matrixes, the transfer law of the deformation matrix is also obtained. The transfer law illuminates the change regularity of internal force or deformation of the remnant structure when certain members are cut off one after another. The results of numerical examples show that the proposed methods are correct, reliable and effective.

关键词： truss structure Redundancy Robustness Topological relationship of structure Removal of members Transfer law

An adaptive reanalysis method for genetic algorithm with application to fast truss optimization

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Acta Mechanica Sinica 2010年第2期26卷 225-234页

作者： Tao Xu Wenjie Zuo Tianshuang Xu Guangcai Song Ruichuan Li State Key Laboratory of Automotive Dynamic Simulation Jilin University 130025 Changchun China Department of Mechanics Jilin University 130025 Changchun China

Although the genetic algorithm （GA） for structural optimization is very robust, it is very computationally intensive and hence slower than optimality criteria and mathematical programming methods. To speed up the design process, the authors present an adaptive reanalysis method for GA and its applications in the optimal design of trusses. This reanalysis technique is primarily derived from the Kirsch＇s combined approximations method. An iteration scheme is adopted to adaptively determine the number of basis vectors at every generation. In order to illustrate this method, three classical examples of optimal truss design are used to validate the proposed reanalysis-based design procedure. The presented numerical results demonstrate that the adaptive reanalysis technique affects very slightly the accuracy of the optimal solutions and does accelerate the design process, especially for large-scale structures.

关键词： truss structure Adaptive reanalysis ·Genetic algorithm ·Fast optimization

Topology Optimization of truss structures Based on Genetic Algorithm

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Topology Optimization of Truss Structures Based on Genetic A...