Search results

1 – 10 of over 2000
To view the access options for this content please click here
Article
Publication date: 18 July 2018

Sangho Ha, Kasin Ransikarbum, Hweeyoung Han, Daeil Kwon, Hyeonnam Kim and Namhun Kim

The purpose of this study is to mitigate the dimensional inaccuracy due to vertical curling/bending deformation of three-dimensional (3D) printed parts produced by…

Abstract

Purpose

The purpose of this study is to mitigate the dimensional inaccuracy due to vertical curling/bending deformation of three-dimensional (3D) printed parts produced by selective laser sintering (SLS) using PA12 based on dimensional compensation of the computer-aided design (CAD) model.

Design/methodology/approach

To carry out this study, specially designed features are initially produced as references, and the dimensional deviations from the vertical bending deformation of the SLS process are analyzed. Next, the deformation patterns are formulated using a polynomial regression model in the global Cartesian coordinates of the building platform. Then, the compensation algorithm is implemented and the original 3D CAD file is preprocessed with an inverse transformation of the features to compensate the deformation errors.

Findings

It was found that the 3D printed parts from the SLS process have the dimensional inaccuracy due to the vertical bending pattern of the quadratic form. By implementing the compensation algorithm, it was statistically shown to effectively reduce bending deformations of various sample parts, including the automotive components, in SLS.

Research limitations/implications

The position of samples in a batch has a direct impact on not only bending deformation but also on horizontal shape geometry error. However, the application of this algorithm is focused on the vertical bending deformation, which is estimated as a major part of dimensional inaccuracy.

Practical implications

This paper provides a practical case study with a real vehicle part. The algorithm was shown to provide a more realistic solution to the dimensional deformation of printed products, which is not manageable by simply using the constant scale factors provided by SLS 3D printer manufacturers.

Originality/value

This paper suggests that the vertical bending deformation from SLS’s 3D printed complex parts can be improved through the proposed compensation algorithm. The compensation algorithm was constructed by using the predictive regression model created from the bending deformation patterns of reference samples. The proposed compensation algorithm can be further used and applied for other complex samples without making additional reference parts.

Details

Rapid Prototyping Journal, vol. 24 no. 6
Type: Research Article
ISSN: 1355-2546

Keywords

To view the access options for this content please click here
Article
Publication date: 6 December 2020

Atilla Savaş

The gas tungsten arc welding (GTAW) process is a widely used process that produces quality weldments. But the high heat generation from the GTAW arc can cause extreme…

Abstract

Purpose

The gas tungsten arc welding (GTAW) process is a widely used process that produces quality weldments. But the high heat generation from the GTAW arc can cause extreme temperatures as high as 20,000°C. The residual stresses and deformations are high accordingly. One of the methods for decreasing residual stresses and deformations is to change the welding pattern. In the literature, there are not so many examples of modeling dealing with welding patterns. This paper aims to investigate the influence of welding patterns on the deformations.

Design/methodology/approach

In this work, back-stepping patterns and partitioning of the weld line were investigated and the distortions and residual stresses were calculated. By doing this, temperature-dependent thermophysical and thermo-mechanical material properties were used. The temperature distribution and deformation from experiments with the same welding conditions were used for validation purposes.

Findings

Seven different welding patterns were analyzed. There is only one pattern with a single partition. There are three patterns investigated for both two and three partitioned weldings. The minimum deformation and the optimum residual stress combination is obtained for the last pattern, which is a three partitioned and diverging pattern.

Originality/value

The most important aspect of this paper is that it deals with welding patterns, which is not much studied beforehand. The other important thing is that the structural part and the thermal part of the simulation were coupled mutually and validated according to experiments.

Details

World Journal of Engineering, vol. 18 no. 2
Type: Research Article
ISSN: 1708-5284

Keywords

To view the access options for this content please click here
Article
Publication date: 1 August 2016

Zhengping Chang, Zhongqi Wang, Bo Jiang, Jinming Zhang, Feiyan Guo and Yonggang Kang

Riveting deformation is inevitable because of local relatively large material flows and typical compliant parts assembly, which affect the final product dimensional…

Abstract

Purpose

Riveting deformation is inevitable because of local relatively large material flows and typical compliant parts assembly, which affect the final product dimensional quality and fatigue durability. However, traditional approaches are concentrated on elastic assembly variation simulation and do not consider the impact of local plastic deformation. This paper aims to present a successive calculation model to study the riveting deformation where local deformation is taken into consideration.

Design/methodology/approach

Based on the material constitutive model and friction coefficient obtained by experiments, an accurate three-dimensional finite element model was built primarily using ABAQUS and was verified by experiments. A successive calculation model of predicting riveting deformation was implemented by the Python and Matlab and was solved by the ABAQUS. Finally, three configuration experiments were conducted to evaluate the effectiveness of the model.

Findings

The model predicting results, obtained from two simple coupons and a wing panel, showed that it was a good compliant with the experimental results, and the riveting sequences had a significant effect on the distribution and magnitude of deformation.

Practical implications

The proposed model of predicting the deformation from riveting process was available in the early design stages, and some efficient suggestions for controlling deformation could be obtained.

Originality/value

A new predicting model of thin-walled sheet metal parts riveting deformation was presented to help the engineers to predict and control the assembly deformation more exactly.

Details

Assembly Automation, vol. 36 no. 3
Type: Research Article
ISSN: 0144-5154

Keywords

To view the access options for this content please click here
Article
Publication date: 23 August 2018

Honglian Cong, Xinxin Li, Aijun Zhang, Yanting Zhang and Jun Zhong

Double-jacquard technique is referred as the most advanced technology for forming patterns on both layers of a 3D fabric knitted on a double-needle bar warp-knitting…

Abstract

Purpose

Double-jacquard technique is referred as the most advanced technology for forming patterns on both layers of a 3D fabric knitted on a double-needle bar warp-knitting machine. In order to realize the computer-aided design and simulation of jacquard patterns, the purpose of this paper is to propose a mathematic model for representation of jacquard structures and an improved mass-spring model to improve the simulation of structural deformation behavior.

Design/methodology/approach

Primarily, it analyzes the jacquard patterning method and displacing principle to design jacquard structures on each layer and linking structures of two layers. Based on that, a loop geometry defined by six key points and segmental lines is built to transfer the jacquard bitmap and lapping movements into a fabric of loops and therefore realizing patterns visualization. Afterwards, an improved mass-spring model is built to simulate structural deformation, in which the fabric is simplified as a mesh of uniformly distributed mass particles. Each loop is treated as a massless particle while underlaps are referred as structural springs connecting loops particles. Elastic forces of these springs on each loop particle is calculated according to the Hook’s law and Newton’s second law, and then based on the explicit Euler’s equations, motion state of each particle is solved including the velocity and the shift.

Findings

Based on the above method, a simulator for double-layer jacquard fabrics is developed via Visual C++ language to visualize the patterned fabrics with pitting effects. With a jacquard shoe fabric as an example, this simulation model is proved to be practical and efficient by comparing the simulation result and real fabric.

Research limitations/implications

Because of limited researches, 3D simulation modeling of this double-layer jacquard fabric will be studied in the further research.

Practical implications

The implement of this simulation method will offer the industries a time-saving and cost-saving approach for new fabrics development.

Originality/value

This approach can be used as a reference for simulating other knitted fabrics with jacquard patterns, such as jacquard garment fabrics and home textile fabrics.

Details

International Journal of Clothing Science and Technology, vol. 30 no. 5
Type: Research Article
ISSN: 0955-6222

Keywords

To view the access options for this content please click here
Article
Publication date: 9 February 2021

Rutu Patil, Veera Venkata Sai Narsimha Gupta Thammana, Awadhesh Kumar Vaishya, Vivek Singh, Sanjeev Kumar and Shreyansh Singh

Additive manufacturing (AM) promises to reduce the weight of the component, it is required to be shown that the mechanical performance of AM parts meets stringent…

Abstract

Purpose

Additive manufacturing (AM) promises to reduce the weight of the component, it is required to be shown that the mechanical performance of AM parts meets stringent industrial design criteria. Very few studies are made on finite element analysis (FEA) of the component produced by AM for real-life workload conditions. This study is supposed to do FEA of the wheel hub, manufactured using metal three-dimensional (3D) printing, under static multi-load conditions and effect of infill pattern on maximum stress, deformation and factor of safety.

Design/methodology/approach

This study conducted FEA on wheel-hub using Ansys. The approach of Orthotropic properties is used to do static analysis of wheel-hub and compared results of different metal 3D printing material (Ti-6Al-4V and Al-Si10-Mg) with hexagonal and triangular infill patterns.

Findings

Ti-6Al-4V with Honeycomb patterns shows better results in all cases and can be replaced with standard conventional material.

Research limitations/implications

Because of the chosen research approach, the research results may lack generalisability. Therefore, it is required to do an experimental study.

Practical implications

Metal components with applications across the automobile industry can be manufactured using AM technology. With the help of AM, components with high strength to weight ratio can be manufactured.

Originality/value

This paper fulfils the identified need of FEA of the component produced by AM for real-life workload conditions. This study is supposed to do FEA of the wheel hub, manufactured using metal 3D printing, under static multi-load conditions and Effect of infill pattern on maximum stress, deformation and factor of safety.

Details

World Journal of Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1708-5284

Keywords

To view the access options for this content please click here
Article
Publication date: 1 April 2003

Ryszard J. Pryputniewicz, David Rosato and Cosme Furlong

Integrity of surface mount technology (SMT) components depends on their response to temperature changes caused by operating conditions. Temperature induced differential…

Abstract

Integrity of surface mount technology (SMT) components depends on their response to temperature changes caused by operating conditions. Temperature induced differential thermal expansions lead to strains in the interconnection structures of active devices. To evaluate these strains, temperature profiles of the interconnected components must be known. In this paper, a methodology for developing thermal models of SMT components is presented using thermal analysis system (TAS) and its application is demonstrated by simulating thermal fields of a representative package. Then, thermomechanical deformations of the package are measured quantitatively using state‐of‐the‐art laser‐based optoelectronic holography (OEH) methodology.

Details

Microelectronics International, vol. 20 no. 1
Type: Research Article
ISSN: 1356-5362

Keywords

To view the access options for this content please click here
Article
Publication date: 29 April 2014

Richard W. Johnson and Yu-Lin Shen

The purpose of this study is to numerically assess the misalignment-induced deformation and its implications, in the through-silicon via (TSV), silicon chip, solder…

Abstract

Purpose

The purpose of this study is to numerically assess the misalignment-induced deformation and its implications, in the through-silicon via (TSV), silicon chip, solder micro-bump, and bonding layer.

Design/methodology/approach

The 3D finite element model features a TSV/micro-bump bonding structure connecting two adjacent silicon (Si) chips, with and without an underfill layer between. A case that the entire solder layer has transformed into an intermetallic layer is also considered.

Findings

The existence of an underfill layer enhances the overall resistance to shear deformation, although with a higher buildup of local stresses. High shear and tensile stresses can develop in the intermetallic and nearby regions of copper and Si if the solder alloy is replaced by an intermetallic layer. The carrier mobility change in Si may be extensively affected by the mechanical action, even in regions far away from the TSV.

Originality/value

This work parametrically explores the trend of stress and deformation fields due to mechanical shear and its influences on the electrical performance of devices. Potential for damage initiation in the TSV/micro-bump is also examined.

Details

Microelectronics International, vol. 31 no. 2
Type: Research Article
ISSN: 1356-5362

Keywords

To view the access options for this content please click here
Article
Publication date: 5 May 2015

Da-Wei Zhang and He Yang

The purpose of this paper is to explore the basic loading state in local loading forming process of large-sized complicated rib-web component, which is important for…

Abstract

Purpose

The purpose of this paper is to explore the basic loading state in local loading forming process of large-sized complicated rib-web component, which is important for understanding process characteristic, controlling metal flow and designing preformed geometry of the local loading forming process. Moreover the analytical models for different loading states are established to quickly predict the metal flow.

Design/methodology/approach

Through analysis of geometric characteristic of large-sized complicated rib-web component and the deformation characteristic on planes of metal flow by local loading method, a representative cross-section is put forward and designed, which could reflect the local loading forming characteristics of large-sized complicated rib-web component. Finite element method (FEM) is used to analyze the stress and metal flow, and the analytical models of metal flow are established by using slab method (SM).

Findings

Three local loading states and one whole loading state are found in the local loading forming process of representative cross-section. Further, four loading states also exist in local loading forming process of large-sized complicated rib-web components. With the metal distribution in the process, some local loading states may turn into whole loading state. For the representative cross-section, the relative error of metal distribution between SM and FEM results is less than 15 per cent, and the relative error of metal in the rib cavity between SM and FEM results is less than 10 per cent.

Originality/value

Metal flow can be controlled by adjusting the loading states in the process. According to the metal flow laws in different loading states, a simple unequal-thickness billet can be designed to achieve initial metal distribution, and then, the secondary metal distribution can be achieved in the process.

Details

Aircraft Engineering and Aerospace Technology: An International Journal, vol. 87 no. 3
Type: Research Article
ISSN: 0002-2667

Keywords

To view the access options for this content please click here
Article
Publication date: 5 April 2011

J.I.V. Sena, R.J. Alves de Sousa and R.A.F. Valente

Incremental sheet forming represents a promising process in the manufacturing of metallic components, particularly its variant known as single point incremental forming…

Abstract

Purpose

Incremental sheet forming represents a promising process in the manufacturing of metallic components, particularly its variant known as single point incremental forming (SPIF). The purpose of this paper is to test and validate the results coming from numerical simulation of SPIF processes using the reduced enhanced solid‐shell formulation, when compared to the solid finite elements available in ABAQUS software. The use of SPIF techniques in the production of small batch components has a potential wide application in fields such as rapid prototyping and biomechanical devices.

Design/methodology/approach

Incremental forming processes differ from conventional stamping by not using a press and by requiring a lower number of tools, since no dedicated punches and dies are necessary, which lowers the overall production costs. In addition, it shows relative simplicity and flexible setup for complex parts, when compared with conventional technologies. However, the low speed of production and low‐dimensional accuracy levels are still the main obstacles for a wider application of this technique in the context of large production batches.

Findings

In this sense, the use of numerical simulation tools based on the finite element method (FEM) can provide a better understanding of the process' peculiarities. However, there are differences on using distinct finite element formulations, regarding accuracy as well as CPU times during simulations, which can be prohibitive in some cases.

Originality/value

Aiming to provide sounding improvements in these two fields (robustness and cost effectiveness of FEM solutions), the present work encloses a preliminary study about some relevant parameters in the FEM simulation of SPIF. Special focus is given to the use of solid‐shell and solid finite elements, for the sake of generality in modelling, as well as implicit solution schemes for the sake of accuracy. Finally, results coming from both experimental data and commercial FEM packages are compared to those obtained by a reliable and cost‐effective solid‐shell finite element formulation developed and implemented by the authors.

Details

Engineering Computations, vol. 28 no. 3
Type: Research Article
ISSN: 0264-4401

Keywords

To view the access options for this content please click here
Article
Publication date: 16 August 2013

Mário Pimentel and Joaquim Figueiras

The purpose of this paper is to present the implementation in a finite element (FE) code of a recently developed material model for the analysis of cracked reinforced…

Abstract

Purpose

The purpose of this paper is to present the implementation in a finite element (FE) code of a recently developed material model for the analysis of cracked reinforced concrete (RC) panels. The model aims for the efficient nonlinear analysis of large‐scale structural elements that can be considered as an assembly of membrane elements, such as bridge girders, shear walls, transfer beams or containment structures.

Design/methodology/approach

In the proposed constitutive model, the equilibrium equations of the cracked membrane element are established directly at the cracks while the compatibility conditions are expressed in terms of spatially averaged strains. This allows the well‐known mechanical phenomena governing the behaviour of cracked concrete elements – such as aggregate interlock (including crack dilatancy effects), tensile fracture and bond shear stress transfer – to be taken into account in a transparent manner using detailed phenomenological models. The spatially averaged stress and strain fields are obtained as a by‐product of the local behaviour at the cracks and of the bond stress transfer mechanisms, allowing the crack spacing and crack widths to be obtained directly from first principles. The model is implemented in an FE code following a total formulation.

Findings

The fact that the updated stresses at the cracks are calculated explicitly from the current spatially averaged total strains and from the updated values of the state variables that are used to monitor damage evolution contributes to the robustness and efficiency of the implementation. Some application examples are presented illustrating the model capabilities and good estimates of the failure modes, failure loads, deformation capacity, cracking patterns and crack widths were achieved.

Originality/value

While being computationally efficient, the model describes the complex stress and strain fields developing in the membrane element, and retrieves useful information for the structural engineer, such as concrete and reinforcement failures as well as the crack spacing and crack widths.

Details

Engineering Computations, vol. 30 no. 6
Type: Research Article
ISSN: 0264-4401

Keywords

1 – 10 of over 2000