Search results

1 – 10 of over 30000
Article
Publication date: 1 June 1997

Jaroslav Mackerle

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…

5388

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.

Details

Engineering Computations, vol. 14 no. 4
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 14 January 2014

Lingtao Yu, Huajian Song, Tao Wang, Zhengyu Wang, Liqiang Sun and Zhijiang Du

The characteristic of static is quite important especially for the manipulator with force feedback. This paper aims to improve the traditional static model by considering…

Abstract

Purpose

The characteristic of static is quite important especially for the manipulator with force feedback. This paper aims to improve the traditional static model by considering the limitations such as lacking of versatility and ignoring gravity of links. For this purpose, a new asymmetric mass distribution method on the analysis of universal “force-sensing” model has been put forward to overcome the limitations.

Design/methodology/approach

Through the forces and torques analysis of every link and the moving platform, the static model of 3-RUU manipulator is acquired. Then, based on the physical meaning analysis of every part in the static model of 3-RUU manipulator, a new asymmetric mass distribution method on the analysis of universal “force-sensing” model can be obtained.

Findings

The correctness of the static model of 3-RUU manipulator is verified by simulation results based on Pro/Engineer software and Adams software. Furthermore, experiment results based on a manipulator similar to the Omega.3 manipulator indicate that the universal “force-sensing” model can be applicable to the above manipulator.

Originality/value

A new asymmetric mass distribution method on the analysis of universal static mathematical model has been put forward. Based on physical meaning of the above method, the “force-sensing” model can be established quickly and it owns versatility, which can be applicable to the 3-RUU manipulator, the Omega.3 parallel manipulator and other similar manipulators with force feedback. In addition, it can improve the accuracy of the “force-sensing” model to a great extent.

Details

Industrial Robot: An International Journal, vol. 41 no. 1
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 18 November 2013

Graeme Guthrie

This paper aims to demonstrate the practical application of real options analysis to the evaluation of multistage projects, using an example involving a commercial real…

2018

Abstract

Purpose

This paper aims to demonstrate the practical application of real options analysis to the evaluation of multistage projects, using an example involving a commercial real estate development.

Design/methodology/approach

The approach demonstrated builds on static discounted cash flow (DCF) analysis and requires knowledge of only the binomial option pricing model.

Findings

Real options analysis can be implemented in a spreadsheet and only one parameter – the volatility of the price of the completed project – needs to be estimated in addition to those required for static DCF analysis. The approach described can be used to evaluate a project at any stage of development, which is especially useful when the suspension of partly completed projects is under consideration.

Originality/value

The paper shows how to carry out real options analysis of complex multistage development projects using straightforward valuation tools, making an important project evaluation technique more readily available to practitioners.

Details

Pacific Accounting Review, vol. 25 no. 3
Type: Research Article
ISSN: 0114-0582

Keywords

Article
Publication date: 5 October 2015

Ali Johari, Jaber Rezvani Pour and Akbar Javadi

Liquefaction of soils is defined as significant reduction in shear strength and stiffness due to increase in pore water pressure. This phenomenon can occur in static

Abstract

Purpose

Liquefaction of soils is defined as significant reduction in shear strength and stiffness due to increase in pore water pressure. This phenomenon can occur in static (monotonic) or dynamic loading patterns. However, in each pattern, the inherent variability of the soil parameters indicates that this problem is of a probabilistic nature rather than being deterministic. The purpose of this paper is to present a method, based on random finite element method, for reliability assessment of static liquefaction of saturated loose sand under monotonic loading.

Design/methodology/approach

The random finite element analysis is used for reliability assessment of static liquefaction of saturated loose sand under monotonic loading. The soil behavior is modeled by an elasto-plastic effective stress constitutive model. Independent soil parameters including saturated unit weight, peak friction angle and initial plastic shear modulus are selected as stochastic parameters which are modeled using a truncated normal probability density function (pdf).

Findings

The probability of liquefaction is assessed by pdf of modified pore pressure ratio at each depth. For this purpose pore pressure ratio is modified for monotonic loading of soil. It is shown that the saturated unit weight is the most effective parameter, within the selected stochastic parameters, influencing the static soil liquefaction.

Originality/value

This research focuses on the reliability analysis of static liquefaction potential of sandy soils. Three independent soil parameters including saturated unit weight, peak friction angle and initial plastic shear modulus are considered as stochastic input parameters. A computer model, coded in MATLAB, is developed for the random finite element analysis. For modeling of the soil behavior, a specific elasto-plastic effective stress constitutive model (UBCSAND) was used.

Article
Publication date: 1 October 2019

Cristiane Oliveira Viana, Hermes Carvalho, José Correia, Pedro Aires Montenegro, Raphael Pedrosa Heleno, Guilherme Santana Alencar, Abilio M.P. de Jesus and Rui Calçada

The purpose of this paper is to evaluate the fatigue process through the dynamic analysis of the global structural model and local static sub-modelling in a critical…

Abstract

Purpose

The purpose of this paper is to evaluate the fatigue process through the dynamic analysis of the global structural model and local static sub-modelling in a critical detail using the hot-spot stress approach. The detail was studied in three different positions at the “Alcácer do Sal” access viaduct, and the methodologies from the IIW and Eurocode EN 1993-1-9 were compared.

Design/methodology/approach

In this study, the fatigue life process based on the hot-spot stress approach was evaluated using a global dynamic analysis and a local sub-modelling based on a static analysis of welded connections in the “Alcácer do Sal” railway structure, Portugal, taking into consideration the recommendations from IIW and Eurocode EN 1993-1-9. The hot-spot stresses were calculated through the static analysis of the sub-model of the welded connection for each vibration mode with the aim to obtain the temporal stresses using the modal coordinates and modal stresses of the extrapolation points. The Ansys® and Matlab® softwares were used for the numerical analysis and the hot-spot stress calculations, respectively.

Findings

The proposed methodology/approach to obtain fatigue assessment is based on the modal analysis of the global structural model and local static sub-modelling. The modal analysis was used to extract the boundary conditions to be used in the local model to determine the temporal stresses of the extrapolation points. Based on the modal superposition method, the stresses as function of time were obtained for fatigue life evaluation of a critical detail by the hot-spot stress approach. The detail was studied in three different positions.

Originality/value

In the present study, a global-local fatigue methodology based on dynamic analysis of the global structural model and local static sub-modelling of the critical detail using the hot-spot stress approach is proposed. Herein, the modal analysis of the global structural model supported by the modal superposition method was used to obtain the matrix of modal coordinates. The static analysis of the local sub-model for each mode from the modal analysis of global structural model was done to estimate the hot-spot stresses. The fatigue damage calculation was based on S-N curve of the critical detail and rainflow method. The IIW recommendation proved to be more conservative compared to the proposed rules in the Eurocode EN 1993-1-9. The global-local modelling based on dynamic analysis is an important and effective tool for fatigue evaluation in welded joints.

Details

International Journal of Structural Integrity, vol. 12 no. 1
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 3 October 2019

Arash Naji

Progressive collapse refers to a phenomenon, in which local damage in a primary structural component leads to total or partial structural system failure, without any…

Abstract

Purpose

Progressive collapse refers to a phenomenon, in which local damage in a primary structural component leads to total or partial structural system failure, without any proportionality between the initial and final damage. Robustness is a measure that demonstrates the strength of a structure to resist progressive collapse. Static pushdown and nonlinear dynamic analysis were two main procedures to calculate the capacity of structures to resist progressive collapse. According to previous works, static analysis would lead to inaccurate results. Meanwhile, capacity analysis by dynamic analysis needs several reruns and encountering numerical instability is inevitable. The purpose of this paper is to present the formulation of a solution procedure to determine robustness of steel moment resisting frames, using plastic limit analysis (PLA).

Design/methodology/approach

This formulation utilizes simplex optimization to solve the problem. Static pushdown and incremental dynamic methods are used for verification.

Findings

The results obtained from PLA have good agreement with incremental analysis results. While incremental dynamic analysis is a very demanding method, PLA can be utilized as an alternative method.

Originality/value

The formulation of progressive collapse resistance of steel moment frames by means of PLA is not proposed in previous research works.

Details

International Journal of Structural Integrity, vol. 11 no. 2
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 1 January 1992

ZHI‐HUA ZHONG and JAROSLAV MACKERLE

Contact problems are among the most difficult ones in mechanics. Due to its practical importance, the problem has been receiving extensive research work over the years…

Abstract

Contact problems are among the most difficult ones in mechanics. Due to its practical importance, the problem has been receiving extensive research work over the years. The finite element method has been widely used to solve contact problems with various grades of complexity. Great progress has been made on both theoretical studies and engineering applications. This paper reviews some of the main developments in contact theories and finite element solution techniques for static contact problems. Classical and variational formulations of the problem are first given and then finite element solution techniques are reviewed. Available constraint methods, friction laws and contact searching algorithms are also briefly described. At the end of the paper, a bibliography is included, listing about seven hundred papers which are related to static contact problems and have been published in various journals and conference proceedings from 1976.

Details

Engineering Computations, vol. 9 no. 1
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 4 September 2017

Marcin Figat

This paper aims to present the results of aerodynamic calculation of impact the main rotor on the fuselage and the tail of a light gyroplane. This kind of vehicle is a…

Abstract

Purpose

This paper aims to present the results of aerodynamic calculation of impact the main rotor on the fuselage and the tail of a light gyroplane. This kind of vehicle is a type of rotorcraft which uses a non-powered rotor in autorotation to develop lift and engine-powered propeller to provide the thrust. Both of them disturb the flow around the gyroplane body (gyroplane fuselage and tail) and influence on its static stability. The main goal of the presented research was to find the magnitude of this influence. To measure this effect, the main stability derivatives changes of gyroplane body were investigated.

Design/methodology/approach

The CFD analysis of the complete gyroplane was made. Computation was performed for the model of gyroplane which was equipped with the two sub-models of the main rotor and the engine-powered propeller. Both of them were modelled as the actuator discs. This method allows to compute the aerodynamic impact of rotating components on the gyroplane body. All aerodynamic analysis was made by the MGAERO software. The numerical code of the software bases on the Euler flow model. Next, the resulting aerodynamic coefficients were used to calculate the most important stability derivatives of the gyroplane body.

Findings

The result obtained by computation presents the change in the most important aerodynamic coefficients and stability derivatives of the gyroplane body caused by the impact of its main rotor. Moreover, the result includes the change of the aerodynamic coefficients and stability derivatives caused by change of the main rotor configuration (change of rotation rate and angle of incidence) and change of the flight condition (gyroplane angle of attack sideslip angle and flight speed).

Practical implications

Analysis of the main rotor impact will be very useful for evaluation of dynamic stability of the light gyroplane. Moreover, the results will be helpful to design the horizontal and vertical tail for the light gyroplane.

Originality/value

This paper presents the method of the numerical analysis of the static stability of the light gyroplane’s body. The results of analysis present the impact of disturbance generated by the rotating main rotor on the static stability of the gyroplane body. Moreover, the impact of the main rotor configuration change and the flight condition change on the static stability were investigated too. The evaluation of the gyroplane’s body static stability was made by the stability derivatives. The methodology and obtained result will be very useful for analysis of the dynamic stability of the light gyroplanes. Moreover, the results will be helpful during design the main components of the gyroplane like vertical and horizontal tail.

Details

Aircraft Engineering and Aerospace Technology, vol. 89 no. 5
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 1 March 1992

ADNAN IBRAHIMBEGOVI&Cacute and EDWARD L. WILSON

This paper presents several methods for enhancing computational efficiency in both static and dynamic analysis of structural systems with localized non‐linear behaviour. A…

Abstract

This paper presents several methods for enhancing computational efficiency in both static and dynamic analysis of structural systems with localized non‐linear behaviour. A significant reduction of computational effort with respect to brute‐force non‐linear analysis is achieved in all cases at the insignificant (or no) loss of accuracy. The presented methodologies are easily incorporated into a standard computer program for linear analysis.

Details

Engineering Computations, vol. 9 no. 3
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 28 June 2018

Artur Lach, Andrzej Katunin and Adam Gnatowski

The paper aims to present a design and numerical verification procedure of a composite casing of a microstrip antenna for an aerospace satellite.

Abstract

Purpose

The paper aims to present a design and numerical verification procedure of a composite casing of a microstrip antenna for an aerospace satellite.

Design/methodology/approach

The casing for the microstrip antenna was designed in a form of a laminate shell with variable number of layers of reinforcing fabric. The material properties, both static and dynamic, were determined experimentally and then exported to an environment of numerical analyses. The numerical modal analysis allows optimizing the geometry and lay-up of the casing in such a way that a number of modal shapes occurring in the operational frequency band was significantly reduced, several modal shapes with high displacement in flanges of the casing were eliminated and the values of natural frequencies were increased. A final model of the composite casing was subjected to two types of analyses which simulate typical operation conditions during spacecraft mission. These analyses contained thermomechanical quasi-static analyses with 12 loadcases and thermomechanical shock analyses with 9 loadcases, which simulate various mechanical and temperature conditions.

Findings

Results of the performed analyses were compared with safety margins determined by following requirements to spacecraft vehicles. The obtained results confirm the design feasibility, which allow considering the proposed design during manufacturing of a prototype in further studies.

Practical implications

Moreover, the presented results can be considered as a design methodology guideline, which can be helpful for engineers working in the aerospace industry.

Originality/value

The originality of the paper lies in the proposed design and verification procedure of composite elements subjected to operational loading during a spacecraft mission.

Details

Aircraft Engineering and Aerospace Technology, vol. 90 no. 5
Type: Research Article
ISSN: 1748-8842

Keywords

1 – 10 of over 30000