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1 – 10 of over 120000Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the…
Abstract
Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the theoretical as well as practical points of view. The range of applications of FEMs in this area is wide and cannot be presented in a single paper; therefore aims to give the reader an encyclopaedic view on the subject. The bibliography at the end of the paper contains 2,025 references to papers, conference proceedings and theses/dissertations dealing with the analysis of beams, columns, rods, bars, cables, discs, blades, shafts, membranes, plates and shells that were published in 1992‐1995.
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Da Teng, Yun-Wen Feng, Jun-Yu Chen and Cheng Lu
The purpose of this paper is to briefly summarize and review the theories and methods of complex structures’ dynamic reliability. Complex structures are usually assembled from…
Abstract
Purpose
The purpose of this paper is to briefly summarize and review the theories and methods of complex structures’ dynamic reliability. Complex structures are usually assembled from multiple components and subjected to time-varying loads of aerodynamic, structural, thermal and other physical fields; its reliability analysis is of great significance to ensure the safe operation of large-scale equipment such as aviation and machinery.
Design/methodology/approach
In this paper for the single-objective dynamic reliability analysis of complex structures, the calculation can be categorized into Monte Carlo (MC), outcrossing rate, envelope functions and extreme value methods. The series-parallel and expansion methods, multi-extremum surrogate models and decomposed-coordinated surrogate models are summarized for the multiobjective dynamic reliability analysis of complex structures.
Findings
The numerical complex compound function and turbine blisk are used as examples to illustrate the performance of single-objective and multiobjective dynamic reliability analysis methods. Then the future development direction of dynamic reliability analysis of complex structures is prospected.
Originality/value
The paper provides a useful reference for further theoretical research and engineering application.
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My purpose is to describe for strategic management scholars in Africa, particularly graduate students and new faculty members, dynamic analysis and its significance in the African…
Abstract
Purpose
My purpose is to describe for strategic management scholars in Africa, particularly graduate students and new faculty members, dynamic analysis and its significance in the African context so as to assist in the study of dynamic phenomena.
Design/methodology/approach
I discuss various types and methods of dynamic analysis. Dynamic analysis has been used extensively in such fields as cognitive psychology, social psychology, and management in Western countries.
Findings
I illustrate the various dynamics by reviewing four illustrative studies. I also provide procedures for studying dynamics in the African context.
Research limitations/implications
I discuss the strengths and limitations of dynamic analysis and suggest ways of maximizing its potential.
Practical implications
The technique is a source particularly for graduate students of strategy in Africa. They can use it to supplement other approaches in studying strategic management phenomena.
Originality/value
This chapter discusses a typology of dynamic analysis consistent with empirical or variable modeling approaches. The lack of such a typology in the context of Africa makes it a valuable contribution. Thus, it fills a contextual gap in the research methodology literature.
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Apostolos Koukouselis, Konstantinos Chatziioannou, Euripidis Mistakidis and Vanessa Katsardi
The design of compliant towers in deep waters is greatly affected by their dynamic response to wave loads as well as by the geometrical and material nonlinearities that appear. In…
Abstract
Purpose
The design of compliant towers in deep waters is greatly affected by their dynamic response to wave loads as well as by the geometrical and material nonlinearities that appear. In general, a nonlinear time history dynamic analysis is the most appropriate one to be applied to capture the exact response of the structure under wave loading. However, this type of analysis is complex and time-consuming. This paper aims to develop a simplified methodology, which can adequately approximate the maximum response yielded by a dynamic analysis by means of a static analysis.
Design/methodology/approach
Various types of time history dynamic analysis are first applied on a detailed structural model, ranging from linear to fully nonlinear, that are used as reference solutions. In the sequel, a simplified analysis model is formulated, capable of reproducing the response of the entire structure with significantly reduced computational cost. In the next stage, this model is used to obtain the linear and nonlinear response spectra of the structure. Finally, these spectra are used to formulate a simplified design approach, based on equivalent static loads.
Findings
This simplified design approach produces good results in cases that the response is mainly governed by the first eigenmode, which is the case when compliant towers are considered.
Originality/value
The present paper borrows ideas from the area of earthquake engineering, where simplified methodologies can be used for the design of a certain class of structures. However, the development of a simplified methodology for the approximation of the dynamic behavior of offshore structures under wave loading is a much more complex problem, which, to the authors’ knowledge, has not been addressed till now.
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This paper gives a bibliographical review of the finite element and boundary element parallel processing techniques from the theoretical and application points of view. Topics…
Abstract
This paper gives a bibliographical review of the finite element and boundary element parallel processing techniques from the theoretical and application points of view. Topics include: theory – domain decomposition/partitioning, load balancing, parallel solvers/algorithms, parallel mesh generation, adaptive methods, and visualization/graphics; applications – structural mechanics problems, dynamic problems, material/geometrical non‐linear problems, contact problems, fracture mechanics, field problems, coupled problems, sensitivity and optimization, and other problems; hardware and software environments – hardware environments, programming techniques, and software development and presentations. The bibliography at the end of this paper contains 850 references to papers, conference proceedings and theses/dissertations dealing with presented subjects that were published between 1996 and 2002.
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This study aims to perform dynamic response analysis of damaged rigid-frame bridges under multiple moving loads using analytical based transfer matrix method (TMM). The effects of…
Abstract
Purpose
This study aims to perform dynamic response analysis of damaged rigid-frame bridges under multiple moving loads using analytical based transfer matrix method (TMM). The effects of crack depth, moving load velocity and damping on the dynamic response of the model are discussed. The dynamic amplifications are investigated for various damage scenarios in addition to displacement time-histories.
Design/methodology/approach
Timoshenko beam theory (TBT) and Rayleigh-Love bar theory (RLBT) are used for bending and axial vibrations, respectively. The cracks are modeled using rotational and extensional springs. The structure is simplified into an equivalent single degree of freedom (SDOF) system using exact mode shapes to perform forced vibration analysis according to moving load convoy.
Findings
The results are compared to experimental data from literature for different damaged beam under moving load scenarios where a good agreement is observed. The proposed approach is also verified using the results from previous studies for free vibration analysis of cracked frames as well as dynamic response of cracked beams subjected to moving load. The importance of using TBT and RLBT instead of Euler–Bernoulli beam theory (EBT) and classical bar theory (CBT) is revealed. The results show that peak dynamic response at mid-span of the beam is more sensitive to crack length when compared to moving load velocity and damping properties.
Originality/value
The combination of TMM and modal superposition is presented for dynamic response analysis of damaged rigid-frame bridges subjected to moving convoy loading. The effectiveness of transfer matrix formulations for the free vibration analysis of this model shows that proposed approach may be extended to free and forced vibration analysis of more complicated structures such as rigid-frame bridges supported by piles and having multiple cracks.
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David J. Teece and Henry J. Kahwaty
The European Union’s Digital Markets Act (DMA) calls for far-reaching changes to the way economic activity will occur in EU digital markets. Before its remedies are imposed, it is…
Abstract
The European Union’s Digital Markets Act (DMA) calls for far-reaching changes to the way economic activity will occur in EU digital markets. Before its remedies are imposed, it is critical to assess their impacts on individual markets, the digital sector, and the overall European economy. The European Commission (EC) released an Impact Assessment in support of the DMA that purports to evaluate it using cost/benefit analysis.
An economic evaluation of the DMA should consider its full impacts on dynamic competition. The Impact Assessment neither assesses the DMA's impact on dynamic competition in the digital economy nor evaluates the impacts of specific DMA prohibitions and obligations. Instead, it considers benefits in general and largely ignores costs. We study its benefit assessments and find they are based on highly inappropriate methodologies and assumptions. A cost/benefit study using inappropriate methodologies and largely ignoring costs cannot provide a sound policy assessment.
Instead of promoting dynamic competition between platforms, the DMA will likely reinforce existing market structures, ossify market boundaries, and stunt European innovation. The DMA is likely to chill R&D by encouraging free riding on the investments of others, which discourages making those investments. Avoiding harm to innovation is critical because innovation delivers large, positive spillover benefits, driving increases in productivity, employment, wages, and prosperity.
The DMA prioritizes static over dynamic competition, with the potential to harm the European economy. Given this, the Impact Assessment does not demonstrate that the DMA will be beneficial overall, and its implementation must be carefully tailored to alleviate or lessen its potential to harm Europe’s economic performance.
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The purpose of this paper is to improve risk assessment processes in airline flight operations by introducing a dynamic risk assessment method.
Abstract
Purpose
The purpose of this paper is to improve risk assessment processes in airline flight operations by introducing a dynamic risk assessment method.
Design/methodology/approach
Fuzzy logic and Bayesian network are used together to form a dynamic structure in the analysis. One of the most challenging factors of the analyses in aviation is to get quantitative data. In this study, the fuzzy data quantification technique is used to perform dynamic risk assessment. Dynamic structure in the analysis is obtained by transforming the bow-tie model into a Bayesian network equivalent.
Findings
In this study, the probability of top-event from fault tree analysis is calculated as 1.51 × 10−6. Effectiveness of the model is measured by comparing the analysis with the safety performance indicator data that reflects past performance of the airlines. If two data are compared with each other, they are at the same order of value, with small difference (0.6 × 10−7).
Originality/value
This study proposes a dynamic model to be used in risk assessment processes in airline flight operations. A dynamic model for safety analysis provides real-time, autonomous and faster risk assessment. Moreover, it can help in the decision-making process and reduce airline response time to undesired states, which means that the proposed model can contribute to the efficiency of the risk management process in airline flight operations.
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Guichen Zhang, Hongtao Zhang, Heng Peng and Yinghua Liu
High-rise tower structures supported by side frame structure and viscous damper in chemical industry can produce plasticity under dynamic loads, such as wind and earthquake, which…
Abstract
Purpose
High-rise tower structures supported by side frame structure and viscous damper in chemical industry can produce plasticity under dynamic loads, such as wind and earthquake, which will heavily influence the long-term safety operation. This paper aims to systematically study the optimization design of these structures by free vibration and dynamic shakedown analysis.
Design/methodology/approach
The transfer matrix method and Euler–Bernoulli beam vibration are used to study the free vibration characteristic of the simplified high-rise tower structure. Then the extended stress compensation method is used to construct the self-equilibrated stress by using the dynamic load vertexes and the lower bound dynamic shakedown analysis for the structure with viscous damper. Using the proposed method, comprehensive parametric studies and optimization are performed to examine the shakedown load of high-rise tower with various supported conditions.
Findings
The numerical results show that the supported frame stiffness, attached damper or spring parameters influence the free vibration and shakedown characters of high-rise tower very much. The dynamic shakedown load is lowered down quickly with external load frequency increasing to the fundamental natural frequency of the structure under spring supported condition, while changed little with the damping connection. The optimized location and parameter of support are obtained under dynamical excitations.
Research limitations/implications
In this study, the high-rise tower structure is simplified as a cantilever beam supported by a short cantilever beam and a damper under repeated dynamic load, and linear elasticity for solid is assumed for free vibration analysis. The current analysis does not account for effects such as large deformation, stochastic external load and nonlinear vibration conditions which will inevitably be encountered and affect the load capacity.
Originality/value
This study provides a comprehensive method for the dynamical optimization of high-rise tower structure by combining free vibration and shakedown analysis.
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Yining Zeng, Rongxing Duan, Shujuan Huang and Tao Feng
This paper aims to deal with the problems of failure dependence and common cause failure (CCF) that arise in reliability analysis of complex systems.
Abstract
Purpose
This paper aims to deal with the problems of failure dependence and common cause failure (CCF) that arise in reliability analysis of complex systems.
Design/methodology/approach
Firstly, a dynamic fault tree (DFT) is used to capture the dynamic failure behaviours and converted into an equivalent generalized stochastic petri net (GSPN) for quantitative analysis. Secondly, an efficient decomposition and aggregation (EDA) theory is combined with GSPN to deal with the CCF problem, which exists in redundant systems. Finally, Birnbaum importance measure (BIM) is calculated based on the EDA approach and GSPN model, and it is used to take decisions for system improvement and fault diagnosis.
Findings
In this paper, a new reliability evaluation method for dynamic systems subject to CCF is presented based on the DFT analysis and the GSPN model. The GSPN model is easy to capture dynamic failure behaviours of complex systems, and the movement of tokens in the GSPN model represent the changes in the state of the systems. The proposed method takes advantage of the GSPN model and incorporates the EDA method into the GSPN, which simplifies the reliability analysis process. Meanwhile, simulation results under different conditions show that CCF has made a considerable impact on reliability analysis for complex systems, which indicates that the CCF should not be ignored in reliability analysis.
Originality/value
The proposed method combines the EDA theory with the GSPN model to improve the efficiency of the reliability analysis.
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