Office
Journal Information
  • 工程力学
    Engineering Mechanics
    (月刊,1984年创刊)
    主管单位:中国科学技术协会
    主办单位:中国力学学会
    主  编:陆新征
    编辑出版:《工程力学》编辑部
    ISSN 1000-4750 CN 11-2595/O3
Top Read Articles
Published in last 1 year |  In last 2 years |  In last 3 years |  All
Please wait a minute...
For Selected: View Abstracts Toggle Thumbnails
AN EXPLICIT TIME-DOMAIN INTEGRATION SCHEME FOR SOLVING EQUATIONS OF MOTION IN STRUCTURAL DYNAMICS BASED ON A TRUNCATED TAYLOR EXPANSION OF ACCELERATION
WEN Ying, TAO Rui
Engineering Mechanics    2018, 35 (11): 26-34.   DOI: 10.6052/j.issn.1000-4750.2017.08.0661
Abstract212)      PDF(pc) (553KB)(70)       Save
The aim of this paper is to present a novel time integration algorithm with a high level of balance among applicability and reliability and computational efficiency for the dynamic analysis of structures. A formula for approximating acceleration with a forth-order degree of accuracy has been developed, based on the Taylor expansion approach. In applying the Taylor expansion method, a truncation parameter is defined to consider the contributions of high-order terms upon the accuracy of predicted results. Through an integration of the obtained acceleration and considering the dynamic equilibrium condition at the initial state of a typical time step, a single-step equation for computing displacement and velocity at the end state is correspondingly developed. A revised acceleration can be obtained from the calculated displacement and velocity through the equations of motion at the end state. In this regard, as compared with the multiple-step integration scheme, it is not required for the present method to temporarily record the state variables of previous steps. From the results of stability analysis, the maximum step length to period ratio within which the obtained responses remain bounded has been increased by 40% in comparison to the central difference method. By carrying out a series of numerical analyses for the purpose of demonstration, it is generally observed from the natural and forced vibration investigations for linear systems that the computational amplitude decay and period elongation were less than 5% even if the ratio between the time step length and system inherent period/load period mounts to 0.2. However, to reduce the effects of amplitude decay and period distortion for the time integration of nonlinear systems, the magnitude of the above mentioned ratio should generally be restricted below 0.1.
Reference | Related Articles | Metrics
A Philosophic Review of Structural Mechanics Methods
LONG Yu-qiu
Engineering Mechanics    DOI: 10.6052/j.issn.1000-4750.2019.01.ST13
Accepted: 21 January 2019

APPLICATION OF GRAPHICS PROCESSING UNIT BASED ALGORITHM IN NONLINEAR RESPONSE ANALYSIS TO COMPLEX HIGH-RISE BUILDING STRUCTURES
LI Hong-yu, TENG Jun, LI Zuo-hua, ZHANG Lu
Engineering Mechanics    2018, 35 (11): 79-85,91.   DOI: 10.6052/j.issn.1000-4750.2017.08.0656
Abstract127)      PDF(pc) (1380KB)(48)       Save
Currently, most of the commercial finite element (FE) softwares are based on the CPU architectures, which causes massively time consuming, low efficiency, and rigor of requirements of hardware during analyzing the nonlinear response of high-rise structures. Meanwhile, the emergence of GPU based algorithms presents significantly superior performance in floating-point operation and parallel computation due to its special configuration. Therefore, GPU based algorithms can provide a feasible solution for the perplexing issues of nonlinear computation of high-rise structures. Our work is to develop a parallel FE algorithm by introducing GPU and to construct a corresponding heterogeneous platform, ultimately leading to speed up the computation. Firstly, the mapping between the degrees of freedom (DOFs) of a refined model and the threads of GPU is formed. Then, the implicit integration algorithm for solving the dynamic response will be parallelized in threads; meanwhile, the strategies of storage are optimized in terms of element-by-element scale and the demand of memory was reduced while solving the equations. All of the GPU based algorithms have been validated by comparing with the experimental results of a shaking table. Moreover, the validated algorithms are extended to apply to the analysis of the elastic-plastic seismic response of a practical high-rise reinforced concrete frame tube structure. The results show that the proposed algorithm can not only guarantee the accuracy but also improve efficiency dramatically in the procedure of structural nonlinear response analyses.
Reference | Related Articles | Metrics
RESEARCH PROGRESS ON DURABILITY OF STRESSED CONCRETE UNDER ENVIRONMENTAL ACTIONS
LUO Da-ming, NIU Di-tao, SU Li
Engineering Mechanics    2019, 36 (1): 1-14,43.   DOI: 10.6052/j.issn.1000-4750.2018.08.ST11
Abstract126)      PDF(pc) (853KB)(125)       Save
Field concrete structures are often working under the coupling effect of mechanical loads and environmental actions. The loads acting on a structure may cause the change of the physical properties of the concrete, and then influence the durability of a concrete structure. The research results of concrete durability have a certain deviation when neglecting the effect of loading. Recent studies on the durability of stressed concrete under the environmental actions are summarized, and the research results of concrete impermeability, concrete neutralization, ion erosion, and freezing-thawing are emphatically introduced, and the prospect of concrete durability research is put forward.
Reference | Related Articles | Metrics
A REVIEW OF ADVANCES IN SEISMIC FRAGILITY RESEARCH ON BRIDGE STRUCTURES
LI Hong-nan, CHENG Hu, WANG Dong-sheng
Engineering Mechanics    2018, 35 (9): 1-16.   DOI: 10.6052/j.issn.1000-4750.2017.04.0280
Abstract96)      PDF(pc) (502KB)(94)       Save
In light of the proposed formal probabilistic framework for the Performance-Based Earthquake Engineering (PBEE), it is required to assess the seismic performance of bridge structures on the basis of probability. Seismic fragility analysis, combining the seismic response analysis and structural capacity analysis, has attracted wide attention. To improve the current level of research on seismic fragility analysis for bridge structures in China, firstly, the historic stage and development process of fragility analysis were reviewed, and studies on the seismic fragility analysis for bridge structures were summarized. Subsequently, the basic theory and research approaches of seismic fragility analysis were introduced in detail, i.e., the empirical analysis approach, theoretical analysis approach and the combined empirical-theoretical analysis approach. In addition, the shortcomings of current studies were analyzed. Furthermore, the application prospective and implications for future studies on seismic fragility analysis of bridge structures were suggested. The results indicate that various problems are needed to investigate as vital topics in the area of seismic fragility analysis for bridge structures, i.e., the consideration of uncertainties in environment, ground motions, site conditions and structural parameters, the selection of suitable ground motion intensity measures (IMs) and engineering demand parameters (EDPs), the correlation between components and their contributions to the seismic performance of bridge system, etc. More complicated issues were also identified involving the studies on site liquefaction, special fields and large-span bridges, which are significant for the development of the bridge structural seismic engineering.
Reference | Related Articles | Metrics
MAIN CONTENTS OF THE STANDARD FOR WIND LOADS ON ROOF STRUCTURES
YANG Qing-shan, TIAN Yu-ji, CHEN Bo, HUANG Guo-qing
Engineering Mechanics    2018, 35 (7): 1-6.   DOI: 10.6052/j.issn.1000-4750.2017.06.ST03
Abstract92)      PDF(pc) (536KB)(50)       Save
This paper comprehensively introduces the main contents of the Standard for Wind Loads on Roof Structures. Regarding the wind-induced response analyses and wind-resisting design for main load-resisting structures of roofs, the nominal values of wind loads on the main structures are expressed by the sum of mean wind pressures and equivalent static wind pressures. The equivalent static wind pressures correspond to extreme responses induced by fluctuating wind loads, which can be obtained by the proposed method for single or multiple targets. On these bases, the design figures and tables of shape factors for the mean wind pressures and equivalent pressure factors for fluctuating wind responses considering multiple targets are presented for different types of roof structures. These include plane truss structures, beam string structures, grid truss structures, spherical/cylindrical shell structures, saddle structures and overhanging structures. The extreme wind pressure coefficients are estimated based on specified methods, which are applicable to different cases of short/long wind pressure samples, to consequently determine the nominal values of wind loads on cladding and components. Furthermore, the design figures and tables of corresponding extreme wind pressure coefficients are proposed for mono-slope, gable, hip roofs of low-rise buildings; roofs of middle-/high-rise buildings; open roofs and overhanging canopies. Generally, in the current Standard for Wind Loads on Roof Structures, the Chinese wind-resisting design specifications for roof structures have been improved by introducing the concepts of equivalent pressure factors for the wind-induced fluctuating responses of main load-resisting structures and the extreme wind pressure coefficients of cladding and components.
Reference | Related Articles | Metrics
A 4-NODE ISOPARAMETRIC ELEMENT FORMULATED WITH GENERALIZED CONFORMING CONDITIONS
CHEN Xiao-ming, LI Yun-gui
Engineering Mechanics    2018, 35 (12): 1-6,14.   DOI: 10.6052/j.issn.1000-4750.2017.09.0706
Abstract91)      PDF(pc) (409KB)(73)       Save
By using optimized generalized conforming conditions to formulate the plane 4-node element Q4, it is proved that the generalized conforming theory can be expanded to the most fundamental isoparametric elements. Based on the second-order additional displacement field of Q6 and QM6, a new form of additional displacement field was overlaid on Q4 to develop a new element GQM6, which is still second-order and formulated with generalized conforming theory. The numerical results show that the generalized conforming conditions can present more relaxed constraints at element sides than numerical integrals used in QM6, thus the new element GQM6 can exhibit better properties especially on the resistances of mesh distortion. The research shows that it i's still valuable to combine the generalized conforming theory with those traditional finite elements deeply.
Reference | Related Articles | Metrics
SENSITIVITY ANALYSIS OF STRUCTURAL TOPOLOGY DESIGN VARIABLES UNDER HARMONIC EXCITATIONS BASED ON GENERALIZED MODAL TRUNCATION AUGMENTATION METHOD
ZHOU Da-wei, CHEN Biao-song, LI Yun-peng, ZHANG Sheng
Engineering Mechanics    2018, 35 (11): 1-7,16.   DOI: 10.6052/j.issn.1000-4750.2017.08.0618
Abstract84)      PDF(pc) (593KB)(69)       Save
Based on the variable density method for structural topology optimization, the analytical sensitivity formulation of the frequency response displacement amplitude of structures under harmonic excitations is proposed using the adjoint method. The generalized modal truncation augmentation method is introduced to obtain high accuracy without high computational cost in contrast to the poor accuracy of the traditional modal displacement method in sensitivity computation. Numerical examples are presented to compare the proposed method with the global finite difference method and other computation methods. The computational results demonstrate the effectiveness of the proposed method in computing accurate sensitivities with high efficiency under different excitation frequencies and different densities of finite element meshes.
Reference | Related Articles | Metrics
FINITE ELEMENT ANALYSIS ON ASEISMIC BEHAVIOR OF HIGH-STRENGTH STEEL BEAM-TO-COLUMN CONNECTIONS IN STEEL FRAMES BASED ON MICROMECHANICS OF FRACTURE
WANG Lei, BAN Hui-yong, SHI Yong-jiu, WANG Yuan-qing
Engineering Mechanics    2018, 35 (11): 68-78.   DOI: 10.6052/j.issn.1000-4750.2017.08.0608
Abstract79)      PDF(pc) (4626KB)(45)       Save
The fracture resistance of beam-to-column connections may affect the overall aseismic performance of steel frames directly, and it is essential for ensuring the design principle in terms of strong connections and weak members. In order to study the fracture behavior of high-strength (HS) steel frame beam-to-column connections subjected to cyclic loading, this paper uses cyclic void growth model (CVGM) to simulate the fracture of the connections. Through the finite element (FE) software ABAQUS, a 3D FE model of beam-to-column connection is developed, with the CVGM being embedded by using the USDFLD program. 21 specimens fabricated from different grades of steel with various configuration details are analyzed through the model and compared with the test results. It is indicated that load-deformation hysteresis curves, bearing capacities, and number of cycles before fracture commencing are in a good agreement with the tests. The results show that:the CVGM has good adequacy for simulating the extremely low-cycle fatigue fracture of the beam-to-column connections under cyclic loading, and it is suitable for different cyclic loading conditions and steel grades. A basic methodology and a valuable reference will be thusly provided for aseismic performance evaluation and anti-fracture design of the HS steel frame beam-to-column connections.
Reference | Related Articles | Metrics
ELASTIC-PLASTIC BUCKLING BEHAVIOR OF STEEL MATERIAL UNDER COMPLEX CYCLIC LOADING PATHS
WANG Yu-hang, YU Jie, WU Qiang
Engineering Mechanics    2018, 35 (7): 24-38.   DOI: 10.6052/j.issn.1000-4750.2017.07.0525
Abstract75)      PDF(pc) (4888KB)(57)       Save
After compressive yielding, local buckling will occur on steel tubes in concrete-filled steel tubular column under complex seismic loading. In a bar-system finite element model (FE model), the seismic response of steel structure members cannot be effectively simulated by steel constitutive models without considering the influence of buckling. To study the buckling behavior of steel under complex cyclic loading, 30 steel specimens with strength grades Q235 and LYP160 were designed, and various complex cyclic loading paths were adopted to obtain the stress-strain hysteretic relation and elastic-plastic buckling behavior of steel under various complex cyclic loading. On the basis of three steel cyclic constitutive models in the literature:Légeron Model, GA Model and DM Model, the predicting results were compared and analyzed with the test results. It can be seen that Légeron Model fails to stimulate the buckling effect of post-compressive yielding steel, and in GA Model, the stress-strain properties of compressive buckling agree well with the experimental results. The unloading stiffness of tension and compression calculated by the DM Model agrees well with the test results.
Reference | Related Articles | Metrics
SIMULATION OF FLUCTUATING WIND VELOCITY CONTINUOUS STOCHASTIC FIELD BY DIMENSION REDUCTION APPROACH
LIU Zhang-jun, YE Yong-you, LIU Zeng-hui
Engineering Mechanics    2018, 35 (11): 8-16.   DOI: 10.6052/j.issn.1000-4750.2017.07.0570
Abstract69)      PDF(pc) (446KB)(49)       Save
Based on the frequency-wavenumber spectrum representation correlating with the standard orthogonal random variables, a hybrid approach of frequency-wavenumber spectrum and a random function for simulating the continuous spatio-temporal stochastic field is proposed by introducing the random function of standard orthogonal random variable sets. Meanwhile, the simulation efficiency of the proposed approach is greatly enhanced by employing Fast Fourier Transform (FFT) algorithm technique. Benefiting from the proposed approach, the probability characteristics of the spatio-temporal stochastic field can be described on the probability density level with only two elementary random variables. Therefore, the complete representative point sets with assigned probabilities of the elementary random variables can be obtained through the number-theoretical method. As a result, the dimension reduction representation of the continuous spatio-temporal stochastic field can be realized. Numerical examples indicate that when using the same number of samples and taking the efficiency and accuracy into consideration at the same time, the proposed approach have a similar simulation result to the conventional frequency-wavenumber spectrum representation. However, the smallest number of the elementary random variables is needed in the proposed approach, which leads to a smaller number of representative samples with a complete probability set. Consequently, it could naturally be combined with the probability density evolutionary method (PDEM) to carry out the accurate analysis of stochastic dynamic response and dynamic reliability assessment of engineering structures. Finally, combining the Kaimal fluctuating wind velocity spectrum with Davenport spatial coherence function, a numerical example of simulation for horizontal-fluctuating-wind velocity continuous stochastic field is presented to verify the accuracy and superiority of the proposed approach.
Reference | Related Articles | Metrics
MESO-SCALE SIMULATIONS ON FLEXURAL FAILURE AND SIZE EFFECT OF REINFORCED CONCRETE BEAMS
JIN Liu, SU Xiao, DU Xiu-li
Engineering Mechanics    2018, 35 (10): 27-36.   DOI: 10.6052/j.issn.1000-4750.2017.06.0436
Abstract67)      PDF(pc) (1663KB)(68)       Save
The sources of size effect on RC members are the heterogeneity of concrete material and the interaction between steel and concrete. From the view of microcosmic, a three-dimensional micromechanical model for reinforced concrete beams was set up. In the model, the concrete heterogeneity was considered, and the interactions between steel and concrete was described by a nonlinear spring element. Base on the well agreement between simulation results and experimental results, the failure behavior of large beams was studied, meanwhile, the change of failure pattern and flexural strength of different size beams under monotonic and cyclic loading were analyzed. The simulation results show that:1) in the working condition of this article, the flexural of RC cantilever beams have the size effect, and the flexural strength decreases with the increase of depth of the beam; 2) under cyclic loading, the bending beam is brittle because of the fatigue of the bonding performance between concrete and steel; 3) compared to monotonic loading, the cantilever beam damage is more brittle and the size effect of nominal flexural strength is more obvious under a cyclic loading condition.
Reference | Related Articles | Metrics
RESEARCH ON ASEISMIC PERFORMANCE OF PRC COUPLING BEAM-HYBRID COUPLED SHEAR WALL SYSTEM
TIAN Jian-bo, SHI Qing-xuan, LIU Yun-he, LI Shen, MA Hui
Engineering Mechanics    2018, 35 (11): 53-67.   DOI: 10.6052/j.issn.1000-4750.2017.07.0575
Abstract67)      PDF(pc) (1873KB)(53)       Save
PRC coupling beam-hybrid coupled shear wall system is a new structural system formed by replacing the concrete coupling beam with the plate-reinforced composite (PRC) coupling beam in traditional reinforced concrete coupled shear walls. It is still lack of systematic research on its aseismic behavior. Therefore, based on the aseismic performance study of the PRC coupling beam with a small span-to-depth ratio, the BS basic model specimen of the PRC coupling beam-hybrid coupled shear wall system is designed. The aseismic behavior of the PRC coupling beam-hybrid coupled shear wall system is analyzed by using the finite element software. The stress distribution of steel plates, reinforcing bars in coupling beams and concrete is investigated. Meanwhile, the plastic hinges developing law of this hybrid coupled shear wall system is also studied. Further, the influence of a coupling ratio, the section size of a coupling beam, the height-width ratio of a single side wall, the total height of a structure, and the role of a slab on the aseismic behavior of the new structural system is studied. It is recommended that the reasonable coupling ratio for the PRC coupling beam-hybrid coupled shear wall system in a high intensity seismic fortification area is from 40% to 60%.
Reference | Related Articles | Metrics
EXPERIMENTAL STUDY ON ASEISMIC BEHAVIOR OF REINFORCED CONCRETE COLUMNS WITH GRADE 600 MPa STEEL BARS
LI Yi-zhu, CAO Shuang-yin, XU Peng-jie, NI Xiang-yong
Engineering Mechanics    2018, 35 (11): 181-189.   DOI: 10.6052/j.issn.1000-4750.2017.08.0659
Abstract67)      PDF(pc) (1358KB)(52)       Save
To investigate the aseismic behavior of RC columns with grade 600 MPa steel bars, five RC columns with grade 600 MPa steel bars and one RC column with conventional steel for comparison were tested under cyclic loading. The effects of steel bar strength, stirrup spacing and axial compression ratio on failure model, hysteretic behavior, bearing capacity and ductility, dissipation capacity, and degradation of stiffness and strength were analyzed. The test results showed that:the failure pattern of specimens is the bending failure, and the bond failure between the grade 600 MPa longitudinal bars and concrete and the fracture of longitudinal bars were observed. The bearing capacity and energy dissipation of specimens increased significantly with the improvement of steel bar strength, while the ductility and energy dissipation capacity of specimens decreased. Increasing the stirrup spacing decreased the ductility and energy dissipation capacity and accelerated the strength degradation of specimens in late loading, but there was little effect on bearing capacity of specimens. It is concluded that the RC columns with grade 600 MPa steel bars has a good aseismic behavior and can be used in aseismic structures by reasonable design.
Reference | Related Articles | Metrics
ADAPTIVE FINITE ELEMENT-DISCRETE ELEMENT ALGORITHM, SOFTWARE ELFEN AND APPLICATION IN STIMULATED RESERVOIR VOLUME OF SHALE
WANG Yong-liang, JU Yang, CHEN Jia-liang, YANG Yong-ming, Li C F
Engineering Mechanics    2018, 35 (9): 17-25,36.   DOI: 10.6052/j.issn.1000-4750.2017.06.0421
Abstract66)      PDF(pc) (18352KB)(33)       Save
The adaptive algorithm of finite element (FE)-discrete element (DE) for fluidic-mechanical-fracture coupling analysis was introduced in this study. The novel computational software ELFEN based on this method was introduced and applied in a three-dimensional mechanism analysis of a staged stimulated reservoir volume of shale. The superconvergent patch recovery (SPR) method was used to obtain the superconvergent FE stress solutions, by which the error of conventional FE stress solutions was estimated. The adaptive local remesh for domains of crack tips was expected to be characterized by efficient analysis strategy and application for more accurate stress solutions and reliable crack propagation path. Numerical examples were given to show the effectivity, reliability and practicability of the numerical algorithm and the software for staged stimulated reservoir volume of single-and multi-horizontal wells with fluidic-mechanical-fracture coupling.
Reference | Related Articles | Metrics
ADVANCES IN RESEARCHES ON STOCHASTIC DAMAGE MODELS OF CONCRETE
YU Zhi-wu, SHAN Zhi
Engineering Mechanics    2018, 35 (8): 1-8,13.   DOI: 10.6052/j.issn.1000-4750.2017.05.ST13
Abstract64)      PDF(pc) (491KB)(53)       Save
The studies on the micro damage mechanism and stochastic damage model are reviewed. Furthermore, the advances in researches on the stochastic damage model of concrete by the team of authors are introduced as well. The micro damage mechanism analysis was obtained by taking into account mode-Ⅱ microcracks, the stochastic damage model (the fiber bundle-irreversible chain model) was proposed and verified by experiments, and an X-ray computed tomography method for the damage quantification of concrete under compression was developed. Additionally, some related conclusions are drawn.
Reference | Related Articles | Metrics
INTENSITY MEASURES FOR SEISMICALLY ISOLATED TALL BUILDINGS
YANG Can-tian, XIE Lin-lin, LI Ai-qun, ZENG De-min, LIU Li-de
Engineering Mechanics    2018, 35 (8): 21-29.   DOI: 10.6052/j.issn.1000-4750.2017.07.0531
Abstract62)      PDF(pc) (702KB)(