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Seismic performance of moment resisting steel frame subjected to earthquake excitations

Fadzli M. NAZRI, Pang Yew KEN

《结构与土木工程前沿(英文)》 2014年 第8卷 第1期   页码 19-25 doi: 10.1007/s11709-014-0240-3

摘要: This study presents static and dynamic assessments on the steel structures. Pushover analysis (POA) and incremental dynamic analysis (IDA) were run on moment resisting steel frames. The IDA study involves successive scaling and application of each accelerogram followed by assessment of the maximum response. Steel frames are subjected to nonlinear inelastic time history analysis for 14 different scaled ground motions, 7 near field and 7 far field. The results obtained from POA on the 3, 6 and 9 storey steel frames show consistent results for both uniform and triangular lateral loading. Uniform loading shows that the steel frames exhibits higher base shear than the triangular loading. The IDA results show that the far field ground motions has caused all steel frame design within the research to collapse while near field ground motion only caused some steel frames to collapse. The POA can be used to estimate the performance-based-seismic-design (PBSD) limit states of the steel frames with consistency while the IDA seems to be quite inconsistent. It is concluded that the POA can be consistently used to estimate the limit states of steel frames while limit state estimations from IDA requires carefully selected ground motions with considerations of important parameters.

关键词: incremental dynamic analysis (IDA)     pushover analysis     performance-based seismic design    

Higher-order mode effects on the seismic performance of tall piers

Zhongguo GUAN, Jianzhong LI, Yan XU, Hao LU

《结构与土木工程前沿(英文)》 2011年 第5卷 第4期   页码 496-502 doi: 10.1007/s11709-011-0131-9

摘要: A comprehensive analysis was conducted to investigate the seismic performance of a typical tall bridge pier through incremental dynamical analysis (IDA). The effect of higher-order modes was studied specifically. The results showed that higher-order modes significantly contributed to the structural seismic response and should not be neglected. Including these modes resulted in an additional hinge midway up the pier. No plastic hinge would occur at this location for conventional bridge piers. Higher-order modes also led to an out-of-phase response between the hinge rotation at the pier bottom and the displacement at the top. This means that the displacement-based seismic design method cannot correctly predict the mechanical state of the critical hinge and therefore is not suitable for use in the seismic design of tall piers. Mistakenly using the displacement-based seismic design method for tall piers may result in a seriously unsafe condition.

关键词: tall bridges     higher-order mode effects     incremental dynamic analysis    

Functional tolerance theory in incremental growth design

YANG Bo, ZE Xiangbo, YANG Tao

《机械工程前沿(英文)》 2007年 第2卷 第3期   页码 336-343 doi: 10.1007/s11465-007-0059-x

摘要: The evolutionary tolerance design strategy and its characteristics are studied on the basis of automation technology in the product structure design. To guarantee a successful transformation from the functional requirement to geometry constraints between parts, and finally to dimension constraints, a functional tolerance design theory in the process of product growth design is put forward. A mathematical model with a correlated sensitivity function between cost and the tolerance is created, in which the design cost, the manufacturing cost, the usage cost, and the depreciation cost of the product are regarded as control constraints of the tolerance allocation. Considering these costs, a multifactor-cost function to express quality loss of the product is applied into the model. In the mathematical model, the minimum cost is used as the objective function; a reasonable process capability index, the assembly function, and assembly quality are taken as the constraints; and depreciation cost in the objective function is expressed as the discount rate terminology in economics. Thus, allocation of the dimension tolerance as the function and cost over the whole lifetime of the product is realized. Finally, a design example is used to demonstrate the successful application of the proposed functional tolerance theory in the incremental growth design of the product.

关键词: successful transformation     mathematical     automation technology     tolerance allocation     minimum    

Formation mechanism and modeling of surface waviness in incremental sheet forming

《机械工程前沿(英文)》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0679-1

摘要: Improving and controlling surface quality has always been a challenge for incremental sheet forming (ISF), whereas the generation mechanism of waviness surface is still unknown, which impedes the widely application of ISF in the industrial field. In this paper, the formation mechanism and the prediction of waviness are both investigated through experiments, numerical simulation, and theoretical analysis. Based on a verified finite element model, the waviness topography is predicted numerically for the first time, and its generation is attributed to the residual bending deformation through deformation history analysis. For more efficient engineering application, a theoretical model for waviness height is proposed based on the generation mechanism, using a modified strain function considering deformation modes. This work is favorable for the perfection of formation mechanism and control of surface quality in ISF.

关键词: surface waviness     incremental sheet forming     numerical simulation     formation mechanism     deformation history    

Numerical analysis of nonlinear dynamic behavior of earth dams

Babak EBRAHIMIAN

《结构与土木工程前沿(英文)》 2011年 第5卷 第1期   页码 24-40 doi: 10.1007/s11709-010-0082-6

摘要: A numerical study is conducted to investigate the dynamic behavior of earth dams. The numerical investigation employs a fully nonlinear dynamic finite difference analysis incorporating a simple elastic perfectly plastic constitutive model to describe the stress-strain response of the soil and the Rayleigh damping to increase the level of hysteretic damping. The extended Masing rules are implemented into the constitutive model to explain more accurately the soil response under general cyclic loading. The soil stiffness and hysteretic damping change with loading history. The procedures for calibrating the constructed numerical model with centrifuge test data and also a real case history are explained. For the latter, the Long Valley (LV) earth dam subjected to the 1980 Mammoth Lake earthquake as a real case-history is analyzed and the obtained numerical results are compared with the real measurements at the site in both the time and frequency domains. Relatively good agreement is observed between computed and measured quantities. It seems that the Masing rules combined with a simple elasto-plastic model gives reasonable numerical predictions. Afterwards, a comprehensive parametric study is carried out to identify the effects of dam height, input motion characteristics, soil behavior, strength of the shell materials and dam reservoir condition on the dynamic response of earth dams. Three real earthquake records with different levels and peak acceleration values (PGAs) are used as input motions. The results show that the crest acceleration decreases when the dam height increases and no amplification is observed. Further, more inelastic behavior and more earthquake energy absorption are observed in higher dams.

关键词: earth dam     numerical     nonlinear response     dynamic analysis     earthquake     dam height    

Nonlinear analysis of cable structures using the dynamic relaxation method

Mohammad REZAIEE-PAJAND, Mohammad MOHAMMADI-KHATAMI

《结构与土木工程前沿(英文)》 2021年 第15卷 第1期   页码 253-274 doi: 10.1007/s11709-020-0639-y

摘要: The analysis of cable structures is one of the most challenging problems for civil and mechanical engineers. Because they have highly nonlinear behavior, it is difficult to find solutions to these problems. Thus far, different assumptions and methods have been proposed to solve such structures. The dynamic relaxation method (DRM) is an explicit procedure for analyzing these types of structures. To utilize this scheme, investigators have suggested various stiffness matrices for a cable element. In this study, the efficiency and suitability of six well-known proposed matrices are assessed using the DRM. To achieve this goal, 16 numerical examples and two criteria, namely, the number of iterations and the analysis time, are employed. Based on a comprehensive comparison, the methods are ranked according to the two criteria. The numerical findings clearly reveal the best techniques. Moreover, a variety of benchmark problems are suggested by the authors for future studies of cable structures.

关键词: nonlinear analysis     cable structure     stiffness matrix     dynamic relaxation method    

Fictitious soil pile model for dynamic analysis of pipe piles under high-strain conditions

《结构与土木工程前沿(英文)》   页码 915-934 doi: 10.1007/s11709-023-0907-8

摘要: A fictitious soil pile (FSP) model is developed to simulate the behavior of pipe piles with soil plugs undergoing high-strain dynamic impact loading. The developed model simulates the base soil with a fictitious hollow pile fully filled with a soil plug extending at a cone angle from the pile toe to the bedrock. The friction on the outside and inside of the pile walls is distinguished using different shaft models, and the propagation of stress waves in the base soil and soil plug is considered. The motions of the pile−soil system are solved by discretizing them into spring-mass model based on the finite difference method. Comparisons of the predictions of the proposed model and conventional numerical models, as well as measurements for pipe piles in field tests subjected to impact loading, validate the accuracy of the proposed model. A parametric analysis is conducted to illustrate the influence of the model parameters on the pile dynamic response. Finally, the effective length of the FSP is proposed to approximate the affected soil zone below the pipe pile toe, and some guidance is provided for the selection of the model parameters.

关键词: fictitious soil pile     soil plug     pipe piles     high-strain dynamic analysis     one-dimensional wave theory     pile dynamics    

Nonlinear dynamic analysis of functionally graded carbon nanotube-reinforced composite plates using MISQ20

《结构与土木工程前沿(英文)》   页码 1072-1085 doi: 10.1007/s11709-023-0951-4

摘要: The main objective of this study is to further extend the mixed integration smoothed quadrilateral element with 20 unknowns of displacement (MISQ20) to investigate the nonlinear dynamic responses of functionally graded carbon nanotube-reinforced composite (FG-CNTRC) plates with four types of carbon nanotube distributions. The smooth finite element method is used to enhance the accuracy of the Q4 element and avoid shear locking without using any shear correction factors. This method yields accurate results even if the element exhibits a concave quadrilateral shape and reduces the error when the element meshing is rough. Additionally, the element stiffness matrix is established by integrating the boundary of the smoothing domains. The motion equation of the FG-CNTRC plates is solved by adapting the Newmark method combined with the Newton–Raphson algorithm. Subsequently, the calculation program is coded in the MATLAB software and verified by comparing it with other published solutions. Finally, the effects of the input parameters on the nonlinear vibration of the plates are investigated.

关键词: carbon nanotube     MISQ20     FG-CNTRC plate     nonlinear vibration     nonlinear dynamic analysis     SFEM    

Comprehensive analysis of the influence of structural and dynamic parameters on the accuracy of nano-precision

Chengyuan LIANG, Fang YUAN, Xuedong CHEN, Wei JIANG, Lizhan ZENG, Xin LUO

《机械工程前沿(英文)》 2019年 第14卷 第3期   页码 255-272 doi: 10.1007/s11465-019-0538-x

摘要: Nano-precision positioning stages are characterized by rigid-flexible coupling systems. The complex dynamic characteristics of mechanical structure of a stage, which are determined by structural and dynamic parameters, exert a serious influence on the accuracy of its motion and measurement. Systematic evaluation of such influence is essential for the design and improvement of stages. A systematic approach to modeling the dynamic accuracy of a nano-precision positioning stage is developed in this work by integrating a multi-rigid-body dynamic model of the mechanical system and measurement system models. The influence of structural and dynamic parameters, including aerostatic bearing configurations, motion plane errors, foundation vibrations, and positions of the acting points of driving forces, on dynamic accuracy is investigated by adopting the H-type configured stage as an example. The approach is programmed and integrated into a software framework that supports the dynamic design of nano-precision positioning stages. The software framework is then applied to the design of a nano-precision positioning stage used in a packaging lithography machine.

关键词: nano-precision positioning stage     analysis and design     structural and dynamic parameters     dynamic accuracy     systematic modeling    

基于ANSYS的悬索桥分析方法研究

谢雪峰,罗喜恒

《中国工程科学》 2012年 第14卷 第5期   页码 101-105

摘要:

用于悬索桥分析的专用程序和通用程序均有其局限性。基于ANSYS平台进行二次开发,主要着眼于鞍座的模拟、顶推的实现、主缆和吊索的无应力长度确定、无应力长度保持不变的方法,并给出润扬大桥算例予以验证,使得用ANSYS分析悬索桥具有了专用程序的精度和通用程序前后处理方便的特性。

关键词: 悬索桥     ANSYS二次开发     鞍座     顶推     无应力长度     迭代    

Structural dynamic analysis of the orbiting scroll wrap in the scroll compressor

Yicai LIU, Yubo XIA, Peng YAN, Yinbin LI, Haibo XIE

《能源前沿(英文)》 2013年 第7卷 第1期   页码 19-25 doi: 10.1007/s11708-012-0223-9

摘要: A deep analysis of orbiting scroll wraps was conducted in this paper by using ANSYS and SolidWorks. Through the modal analysis, the involute of the circle profile orbiting scroll wrap demonstrated a large span in natural frequencies, which led to more superiority in avoiding structural resonances. Based on the dynamic harmonic analysis, loads of frequency changes were gained and the stress and strain distribution of the orbiting scroll wrap in the most dangerous working conditions were obtained, which determined the segments with maximum stress and strain-displacement properties. Two paths defined to elucidate further the structural characteristics of the exhaust chamber provided evidence for the initial correction of orbiting wraps. The results of the present study offer a theoretical basis for the design and manufacture of scroll wraps, and providing a new way to evaluate different scroll wraps.

关键词: scroll compressor     orbiting scroll wrap     model analysis     harmonic analysis    

Mesh relationship modeling and dynamic characteristic analysis of external spur gears with gear wear

《机械工程前沿(英文)》 2022年 第17卷 第1期   页码 9-9 doi: 10.1007/s11465-021-0665-z

摘要: Gear wear is one of the most common gear failures, which changes the mesh relationship of normal gear. A new mesh relationship caused by gear wear affects meshing excitations, such as mesh stiffness and transmission error, and further increases vibration and noise level. This paper aims to establish the model of mesh relationship and reveal the vibration characteristics of external spur gears with gear wear. A geometric model for a new mesh relationship with gear wear is proposed, which is utilized to evaluate the influence of gear wear on mesh stiffness and unloaded static transmission error (USTE). Based on the mesh stiffness and USTE considering gear wear, a gear dynamic model is established, and the vibration characteristics of gear wear are numerically studied. Comparison with the experimental results verifies the proposed dynamic model based on the new mesh relationship. The numerical and experimental results indicate that gear wear does not change the structure of the spectrum, but it alters the amplitude of the meshing frequencies and their sidebands. Several condition indicators, such as root-mean-square, kurtosis, and first-order meshing frequency amplitude, can be regarded as important bases for judging gear wear state.

关键词: gear wear     mesh relationship     mesh stiffness     transmission error     vibration characteristics    

Static and dynamic analysis of functionally graded fluid-infiltrated porous skew and elliptical nanoplates

《结构与土木工程前沿(英文)》 2023年 第17卷 第3期   页码 477-502 doi: 10.1007/s11709-023-0918-5

摘要: The analysis of static bending and free and forced vibration responses of functionally graded fluid-infiltrated porous (FGFP) skew and elliptical nanoplates placed on Pasternak’s two-parameter elastic foundation is performed for the first time using isogeometric analysis (IGA) based on the non-uniform rational B-splines (NURBSs) basis function. Three types of porosity distributions affect the mechanical characteristics of materials: symmetric distribution, upper asymmetric distribution, and lower asymmetric distribution. The stress–strain relationship for Biot porous materials was determined using the elastic theory. The general equations of motion of the nanoplates were established using the four-unknown shear deformation plate theory in conjunction with the nonlocal elastic theory and Hamilton’s principle. A computer program that uses IGA to determine the static bending and free and forced vibration of a nanoplate was developed on MATLAB software platform. The accuracy of the computational program was validated via numerical comparison with confidence assertions. This set of programs presents the influence of the following parameters on the static bending and free and forced vibrations of nanoplates: porosity distribution law, porosity coefficient and geometrical parameters, elastic foundation, deviation angle, nonlocal coefficient, different boundary conditions, and Skempton coefficients. The numerical findings demonstrated the uniqueness of the FGFP plate’s behavior when the porosities are saturated with liquid compared with the case without liquid. The findings of this study have significant implications for engineers involved in the design and fabrication of the aforementioned type of structures. Furthermore, this can form the basis for future research on the mechanical responses of the structures.

关键词: static bending     free and forced vibrations     nonlocal theory     isogeometric analysis     fluid-infiltrated porous nanoplates    

A fast and accurate dynamic relaxation scheme

Mohammad REZAIEE-PAJAND, Mohammad MOHAMMADI-KHATAMI

《结构与土木工程前沿(英文)》 2019年 第13卷 第1期   页码 176-189 doi: 10.1007/s11709-018-0486-2

摘要: Dynamic relaxation method (DRM) is one of the suitable numerical procedures for nonlinear structural analysis. Adding the fictitious inertia and damping forces to the static equation, and turning it to the dynamic system, are the basis of this technique. Proper selection of the DRM artificial factors leads to the better convergence rate and efficient solutions. This study aims to increase the numerical stability, and to decrease the analysis time. To fulfil this objective, the reduction rate of analysis error for consecutive iterations is minimized. Based on this formulation, a new time step is found for the viscous dynamic relaxation. After combining this novel relationship with the other DRM factors, various geometrical nonlinear structures, such as, trusses, frames and shells are analyzed. The obtained results verify the efficiency of authors’ scheme.

关键词: viscous dynamic relaxation     time step     displacement error     geometric nonlinear analysis    

标题 作者 时间 类型 操作

Seismic performance of moment resisting steel frame subjected to earthquake excitations

Fadzli M. NAZRI, Pang Yew KEN

期刊论文

Higher-order mode effects on the seismic performance of tall piers

Zhongguo GUAN, Jianzhong LI, Yan XU, Hao LU

期刊论文

黄幼麟:Dynamic Consumer Preferences for Electric Vehicles — A Longitudinal Analysis(2020年7月12日)

2022年06月10日

会议视频

Functional tolerance theory in incremental growth design

YANG Bo, ZE Xiangbo, YANG Tao

期刊论文

Formation mechanism and modeling of surface waviness in incremental sheet forming

期刊论文

Numerical analysis of nonlinear dynamic behavior of earth dams

Babak EBRAHIMIAN

期刊论文

Nonlinear analysis of cable structures using the dynamic relaxation method

Mohammad REZAIEE-PAJAND, Mohammad MOHAMMADI-KHATAMI

期刊论文

Fictitious soil pile model for dynamic analysis of pipe piles under high-strain conditions

期刊论文

Nonlinear dynamic analysis of functionally graded carbon nanotube-reinforced composite plates using MISQ20

期刊论文

Comprehensive analysis of the influence of structural and dynamic parameters on the accuracy of nano-precision

Chengyuan LIANG, Fang YUAN, Xuedong CHEN, Wei JIANG, Lizhan ZENG, Xin LUO

期刊论文

基于ANSYS的悬索桥分析方法研究

谢雪峰,罗喜恒

期刊论文

Structural dynamic analysis of the orbiting scroll wrap in the scroll compressor

Yicai LIU, Yubo XIA, Peng YAN, Yinbin LI, Haibo XIE

期刊论文

Mesh relationship modeling and dynamic characteristic analysis of external spur gears with gear wear

期刊论文

Static and dynamic analysis of functionally graded fluid-infiltrated porous skew and elliptical nanoplates

期刊论文

A fast and accurate dynamic relaxation scheme

Mohammad REZAIEE-PAJAND, Mohammad MOHAMMADI-KHATAMI

期刊论文