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Article
Publication date: 1 August 1999

Jaroslav Mackerle

This paper gives a bibliographical review of the finite element methods (FEMs) applied to the analysis of ceramics and glass materials. The bibliography at the end of the paper…

2605

Abstract

This paper gives a bibliographical review of the finite element methods (FEMs) applied to the analysis of ceramics and glass materials. The bibliography at the end of the paper contains references to papers, conference proceedings and theses/dissertations on the subject that were published between 1977‐1998. The following topics are included: ceramics – material and mechanical properties in general, ceramic coatings and joining problems, ceramic composites, ferrites, piezoceramics, ceramic tools and machining, material processing simulations, fracture mechanics and damage, applications of ceramic/composites in engineering; glass – material and mechanical properties in general, glass fiber composites, material processing simulations, fracture mechanics and damage, and applications of glasses in engineering.

Details

Engineering Computations, vol. 16 no. 5
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 24 March 2021

Hsin-Hsien Liu and Hsuan-Yi Chou

Taking a mental accounting theory perspective, this study explores how pricing strategy (all-inclusive vs partitioned) influences consumers' perceived residual value of a product…

Abstract

Purpose

Taking a mental accounting theory perspective, this study explores how pricing strategy (all-inclusive vs partitioned) influences consumers' perceived residual value of a product and their subsequent intentions to upgrade to a newer model.

Design/methodology/approach

A pilot study and two formal experiments were conducted to test the hypotheses.

Findings

A partitioned (vs all-inclusive) price causes consumers to later recall a lower total cost and perceive lower residual value for the existing product, thereby increasing upgrade intentions. This finding holds for both utilitarian and hedonic products. Perceived residual value mediates the impact of the pricing strategy on upgrade intentions. The pricing strategy effect is stronger for state-oriented individuals than for action-oriented individuals.

Originality/value

This study extends understanding of the impact of pricing strategies from consumers' short-term immediate demand to long-term upgrade intentions. It also identifies a previously uninvestigated moderator (action-state orientation), clarifying the boundary conditions of pricing strategy effects. The study's conceptual framework links pricing strategy, sunk costs, perceived residual value and upgrade intentions, providing rich insights and potential research paths. These findings further enhance understanding of upgrade intentions.

Details

Marketing Intelligence & Planning, vol. 39 no. 5
Type: Research Article
ISSN: 0263-4503

Keywords

Article
Publication date: 28 March 2023

Minting Wang, Renjie Cao, HuiChao Chang and Dong Liang

Laser-based powder bed fusion (LPBF) is a new method for forming thin-walled parts, but large cooling rates and temperature gradients can lead to large residual stresses and…

Abstract

Purpose

Laser-based powder bed fusion (LPBF) is a new method for forming thin-walled parts, but large cooling rates and temperature gradients can lead to large residual stresses and deformations in the part. This study aims to reduce the residual stress and deformation of thin-walled parts by a specific laser rescanning strategy.

Design/methodology/approach

A three-dimensional transient finite element model is established to numerically simulate the LPBF forming process of multilayer and multitrack thin-walled parts. By changing the defocus amount, the laser in situ annealing process is designed, and the optimal rescanning parameters are obtained, which are verified by experiments.

Findings

The results show that the annealing effect is related to the average surface temperature and scan time. When the laser power is 30 W and the scanning speed is 20 mm/s, the overall residual stress and deformation of the thin-walled parts are the smallest, and the in situ annealing effect is the best. When the annealing frequency is reduced to once every three layers, the total annealing time can be reduced by more than 60%.

Originality/value

The research results can help better understand the influence mechanism of laser in situ annealing process on residual stress and deformation in LPBF and provide guidance for reducing residual stress and deformation of LPBF thin-walled parts.

Article
Publication date: 14 March 2019

Mohammad Zaman Kabir and Mehdi Parvizi

The purpose of this paper is to focus on the influences of residual stresses which were induced during roll-forming sections on lateral-torsional buckling of thin-walled…

Abstract

Purpose

The purpose of this paper is to focus on the influences of residual stresses which were induced during roll-forming sections on lateral-torsional buckling of thin-walled cold-formed steel channel and built-up I-sections beams. Built-up I section is made up of two back-to-back cold-formed channel beams. In this direction, at the primary stage, the roll-forming process of a channel section was simulated in ABAQUS environment and the accuracy of the result was verified with those existing experiments. Residual stresses and strains in both longitudinal and circumferential transverse directions were extracted and considered in the lateral-torsional buckling analysis under uniform end moments. The contribution of the current research is devoted to the numerical simulation of the rolling process in ABAQUS software enabling to restore the remaining stresses and strains for the buckling analysis in the identical software. The results showed that the residual stresses decrease considerably the lateral-torsional buckling strength as they have a major impact on short-span beams for channel sections and larger span for built-up I sections. The obtained moment capacity from the buckling analysis was compared to the predictions by American Iron and Steel Institute design code and it is found to be conservative.

Design/methodology/approach

This paper has explained a numerical study on the roll-forming process of a channel section and member moment capacities related to the lateral-torsional buckling of the rolled form channel and built-up I-sections beams under uniform bending about its major axis. It has also investigated the effects of residual stresses and strains on the behaviour of this buckling mode.

Findings

The residuals decrease the moment capacities of the channel beams and have major effect on shorter spans and also increase the local buckling strength of compression flange. But the residuals have major effect on larger spans for built-up I sections. It could be seen that the ratio of moment (with residuals and without residuals) for singly symmetric sections is more pronounced than doubly symmetric sections. So it is recommended to use doubly symmetric section of cold-formed section beams.

Originality/value

The incorporation of residual stresses and strains in the process of numerical simulation of rolled forming of cold-formed steel sections under end moments is the main contribution of the current work. The effect of residual stresses and strains on the lateral-torsional buckling is, for the first time, addressed in the paper.

Details

International Journal of Structural Integrity, vol. 10 no. 2
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 8 March 2011

Miguel Morales, Carlos Correa, Juan Antonio Porro, Carlos Molpeceres and José Luis Ocaña

Laser shock peening (LSP) is mainly a mechanical process, but in some cases, it is performed without a protective coating and thermal effects are present near the surface. The…

Abstract

Purpose

Laser shock peening (LSP) is mainly a mechanical process, but in some cases, it is performed without a protective coating and thermal effects are present near the surface. The numerical study of thermo‐mechanical effects and process parameter influence in realistic conditions can be used to better understand the process.

Design/methodology/approach

A physically comprehensive numerical model (SHOCKLAS) has been developed to systematically study LSP processes with or without coatings starting from laser‐plasma interaction and coupled thermo‐mechanical target behavior. Several typical results of the developed SHOCKLAS numerical system are presented. In particular, the application of the model to the realistic simulation (full 3D dependence, non‐linear material behavior, thermal and mechanical effects, treatment over extended surfaces) of LSP treatments in the experimental conditions of the irradiation facility used by the authors is presented.

Findings

Target clamping has some influence on the results and needs to be properly simulated. An increase in laser spot radius and an increase in pressure produces an increase of the maximum compressive residual stress and also the depth of the compressive residual stress region. By increasing the pulse overlapping density, no major improvements are obtained if the pressure is high enough. The relative influence of thermal/mechanical effects shows that each effect has a different temporal scale and thermal effects are limited to a small region near the surface and compressive residual stresses very close to the surface level can be induced even without any protective coating through the application of adjacent pulses.

Originality/value

The paper presents numerical thermo‐mechanical study for LSP treatments without coating and a study of the influence of several process parameters on residual stress distribution with consideration of pulse overlapping.

Details

International Journal of Structural Integrity, vol. 2 no. 1
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 15 November 2013

Dirk Schnubel, Manfred Horstmann and Norbert Huber

While normally the formation of thermally induced residual stresses is seen mainly as detrimental side effect from production processes like welding or casting, the well-directed…

Abstract

Purpose

While normally the formation of thermally induced residual stresses is seen mainly as detrimental side effect from production processes like welding or casting, the well-directed introduction of thermal residual stresses can also be used as tool to retard fatigue crack growth (FCG). In the presented paper, the use of a defocused laser to modify the residual stress state, and by that to retard the FCG, is examined. The focus lies on the simulation-based optimisation of the heating line position for achieving a maximum fatigue life. The paper aims to discuss these issues.

Design/methodology/approach

In the presented work, the developed prediction methodology for the FCG coupling process simulation and subsequent fracture mechanics analysis is used to identify the optimum positioning of either one or two heating lines on a C(T)100 specimen that leads to a maximised total lifetime. Afterwards, the prediction results are validated experimentally for selected cases.

Findings

The predictions match the experiments within the experimental scatter indicating the correct identification of the optimum heating line positions. This demonstrates the large potential for reducing the experimental effort needed for design optimisation using the proposed strategy.

Originality/value

The used methodology of coupling of welding simulation with subsequent fracture mechanics analysis in order to optimise the FCG behaviour of structures is innovative and only very few published studies addressed parts of similar approaches.

Details

International Journal of Structural Integrity, vol. 4 no. 4
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 27 September 2021

Xushan Zhao, Yuanxun Wang, Guilan Wang, Runsheng Li and Haiou Zhang

This paper aims to summarize the influence law of hybrid deposited and micro-rolling (HDMR) technology on the shaping strain and residual stress. And the rolling parameters…

Abstract

Purpose

This paper aims to summarize the influence law of hybrid deposited and micro-rolling (HDMR) technology on the shaping strain and residual stress. And the rolling parameters combination was further optimized to guide the actual production.

Design/methodology/approach

This paper proposed a three-dimensional coupled thermo-mechanical model of the HDMR process. The validated model is used to investigate the influences of rolling parameters on stress and plastic strain (the distance between the energy source and roller [De–r], the rolling compression [cr] and the friction coefficient [fr]). The orthogonal optimization of three factors and three levels was carried out. The influence of rolling parameters on the plastic strain and residual stress is analyzed.

Findings

The simulation results show that HDMR technology can effectively increase the shaping strain of the weld bead and reduce the residual tensile stress on the weld bead surface. Furthermore, the influence of rolling parameters on stress and strain is obtained by orthogonal analysis, and the corresponding optimal combination is proposed. Also, the rolling temperature significantly affects the residual stress, and the rolling reduction has a substantial effect on the plastic deformation.

Research limitations/implications

Owing to the choice of research methods, this paper failed to study microstructure evolution.

Originality/value

This paper provides a reference principle for the optimal selection of rolling parameters in HDMR.

Details

Rapid Prototyping Journal, vol. 28 no. 3
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 1 January 2009

X.Q. Zhang

widely‐used hypoelastic model for four well‐known objective stress rates under a four‐phase stress cycle associated with axial tension and/or torsion of thin‐walled cylindrical…

Abstract

widely‐used hypoelastic model for four well‐known objective stress rates under a four‐phase stress cycle associated with axial tension and/or torsion of thin‐walled cylindrical tubes. Here, two kinds of models based upon the Cauchy stress and the Kirchhoff stress will be treated. The reduced systems of differential equations of these rate constitutive equations are derived and studied for Jaumann, Green‐ Naghdi, logarithmic and Truesdell stress rates, separately. Analytical solutions in some cases and numerical solutions in all cases are obtained using these reduced systems. Comparisons between the residual deformations are made for different cases. It may be seen that only the logarithmic stress rate results in no residual deformation. In particular, results indicate that Green‐Naghdi rate would generate unexpected residual deformation effect that is essentially different from that resulting from Jaumann rate. On the other hand, it is realized that this study accomplishes an alternative, direct proof for the nonintegrability problem of Truesdell’s hypoelastic rate equation with classical stress rates. This problem has been first treated successfully by Simo and Pister in 1984 using Bernstein’s integrability conditions. However, such treatment needs to cope with a coupled system of nonlinear partial differential equations in Cauchy stress. Here, a different idea is used. It is noted that every integrable hypoelastic equation is just an equivalent rate form of an elastic equation and hence should produce no residual deformations under every possible stress cycle. Accordingly, a hypoelastic model with a stress rate has to be non‐integrable, whenever a stress cycle can be found under which this model generates residual deformation. According to this idea of reductio ad absurdum, a well‐designed stress cycle is introduced and the corresponding residual deformations are calculated. Unlike the treatment of Bernstein’s integrability conditions, it may be a simple and straightforward matter to calculate the final deformations for a given stress cycle. This has been done in this study for several well‐known stress rates.

Details

Multidiscipline Modeling in Materials and Structures, vol. 5 no. 1
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 1 February 1989

C.T. Karlsson

Single‐pass girth butt welding of a carbon‐manganese pipe is studied numerically using the finite element codes ADINAT/ADINA. A rotationally symmetric finite element model is…

Abstract

Single‐pass girth butt welding of a carbon‐manganese pipe is studied numerically using the finite element codes ADINAT/ADINA. A rotationally symmetric finite element model is employed in both the thermal and mechanical analysis. This model is used to investigate the influence on the residual stress state of pipe geometry, mesh density and material modelling. The results from the present study are compared with previous results from two different FE analyses and an experimental investigation. One of the FE analyses was fully three dimensional and the other employed shell elements. The calculated residual stresses were found to differ significantly only when different material models were employed. The thermal strain seemed to be the material parameter with the largest influence on the residual stress state. Especially the changes in thermal strain during phase transformations seemed to have a great influence. This means that the temperature field should be determined accurately enough to predict when and where the different phase transformations occur. Almost the same residual stresses were obtained for two pipes with different pipe geometries and weld parameters.

Details

Engineering Computations, vol. 6 no. 2
Type: Research Article
ISSN: 0264-4401

Article
Publication date: 28 November 2019

Makram Elfarhani, Ali Mkaddem, Ahmed A. Alzahrani, Abdullah S. Bin Mahfouz, Abdessalem Jarraya and Mohamed Haddar

The efficiency of fractional derivative and hereditary combined approach in modeling viscoelastic behavior of soft foams was successfully addressed in Elfarhani et al. (2016a)…

Abstract

Purpose

The efficiency of fractional derivative and hereditary combined approach in modeling viscoelastic behavior of soft foams was successfully addressed in Elfarhani et al. (2016a). Since predictions obtained on flexible polyurethane foam (FPF) type A (density 28 kg m−3) were found very promoting, the purpose of this paper is to apply the approach basing on two other types of foams. Both soft polyurethane foams type B of density 42 kg m−3 and type C of density 50 kg m−3 were subjected to multi-cycles compressive tests.

Design/methodology/approach

The total foam response is assumed to be the sum of a non-linear elastic component and viscoelastic component. The elastic force is modeled by a seven-order polynomial function of displacement. The hereditary approach was applied during the loading half-cycles to simulate the short memory effects while the fractional derivative approach was applied during unloading cycles to simulate the long memory effects. An identification methodology based on the separation of the measurements of each component force was developed to avoid parameter admixture problems.

Findings

The proposed model reveals good reliability in predicting the responses of the two considered flexible foams. Predictions as measurements establish that residual responses were negligible compared to elastic and viscoelastic damping responses.

Originality/value

The development of a new combined model reveals good reliability in predicting the responses of the two polyurethane foams type A and B.

Details

Multidiscipline Modeling in Materials and Structures, vol. 16 no. 3
Type: Research Article
ISSN: 1573-6105

Keywords

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