Xun Xu, Haidong Yu, Yunyong Li and Xinmin Lai
The structure stiffness is greatly affected by the fixture constraints during assembly due to the flexibility of large-scale thin-walled structures. The compliant deformation of…
Abstract
Purpose
The structure stiffness is greatly affected by the fixture constraints during assembly due to the flexibility of large-scale thin-walled structures. The compliant deformation of structures is usually not consistent for the non-uniform stiffness in various clamping schemes. The purpose of this paper is to investigate the correlation between the assembly quality and the clamping schemes of structures with various initial deviations and geometrical parameters, which is based on the proposed irregular quadrilateral plate element via absolute nodal coordinate formulation (ANCF).
Design/methodology/approach
Two typical clamping schemes are specified for the large-scale thin-walled structures. Two typical deviation modes are defined in both free and clamping states in the corresponding clamping schemes. The new irregular quadrilateral plate element via ANCF is validated to analyze the compliant deformation of assembled structures. The quasi-static force equilibrium equations are extended considering the factors of clamping constraints and geometric deviations.
Findings
The initial deviations and geometrical parameters strongly affect the assembly deviations of structures in two clamping schemes. The variation tendencies of assembly deviations are demonstrated in details with the circumferential clamping position and axial clamping position in two clamping schemes, providing guidance to optimize the fixture configuration. The assembly quality of structures with deviations can be improved by configuration synthesis of the clamping schemes.
Originality/value
Typical over-constraint clamping schemes and deviation modes in clamping states are defined for large-scale thin-walled structures. The plate element via ANCF is extended to analyze the assembly deviations of thin-walled structures in various clamping schemes. Based on the proposed theoretical model, the effects of clamping schemes and initial deviations on the deformation and assembly deviation propagation of structures are investigated.
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Kunyong Chen, Yong Zhao, Yuming Liu, Haidong Yu and Shunzhou Huang
This paper aims to propose an optimization method to automatically adjust the spatial route of multibend pipes to meet the assembly demands in constrained space.
Abstract
Purpose
This paper aims to propose an optimization method to automatically adjust the spatial route of multibend pipes to meet the assembly demands in constrained space.
Design/methodology/approach
The compact geometric parameters that uniquely determine the pipe route are analyzed. Besides, the relationship between these parameters and the end pose is revealed based on the exponential product formula. Mathematical representations for the engineering constraints, including the end pose restriction, collision interference, manufacture ability and geometric limitations, are further established. On this basis, the adjustment of the spatial route is formulated as a multiconstraint optimization problem. A modified particle swarm optimization method based on the combination of gradient projection and swarm intelligence is designed to find the near-optimal pipe that meets the required assembly demands.
Findings
The experimental results show that the proposed method can effectively find the feasible pipe route that satisfies the engineering constraints and the end pose requirement is highly guaranteed.
Originality/value
The proposed method can automate the geometric adjustment of multi-bend pipes to meet the actual assembly demands, which significantly reduces manual efforts and guarantees high accuracy. The results demonstrate the possibility of further applications in the pipe assembly or design process, especially in ships, aerospace products or pressure vessels.
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Yong Qin and Haidong Yu
This paper aims to provide a better understanding of the challenges and potential solutions in Visual Simultaneous Localization and Mapping (SLAM), laying the foundation for its…
Abstract
Purpose
This paper aims to provide a better understanding of the challenges and potential solutions in Visual Simultaneous Localization and Mapping (SLAM), laying the foundation for its applications in autonomous navigation, intelligent driving and other related domains.
Design/methodology/approach
In analyzing the latest research, the review presents representative achievements, including methods to enhance efficiency, robustness and accuracy. Additionally, the review provides insights into the future development direction of Visual SLAM, emphasizing the importance of improving system robustness when dealing with dynamic environments. The research methodology of this review involves a literature review and data set analysis, enabling a comprehensive understanding of the current status and prospects in the field of Visual SLAM.
Findings
This review aims to comprehensively evaluate the latest advances and challenges in the field of Visual SLAM. By collecting and analyzing relevant research papers and classic data sets, it reveals the current issues faced by Visual SLAM in complex environments and proposes potential solutions. The review begins by introducing the fundamental principles and application areas of Visual SLAM, followed by an in-depth discussion of the challenges encountered when dealing with dynamic objects and complex environments. To enhance the performance of SLAM algorithms, researchers have made progress by integrating different sensor modalities, improving feature extraction and incorporating deep learning techniques, driving advancements in the field.
Originality/value
To the best of the authors’ knowledge, the originality of this review lies in its in-depth analysis of current research hotspots and predictions for future development, providing valuable references for researchers in this field.
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Yunyong Li, Yong Zhao, Haidong Yu and Xinmin Lai
A new deviation propagation model considering the form defects in compliant assembly process is proposed. The purpose of this paper is to analyze the deviation propagation by…
Abstract
Purpose
A new deviation propagation model considering the form defects in compliant assembly process is proposed. The purpose of this paper is to analyze the deviation propagation by using the basic deviation fields. In particular, each basic deviation field is defined with a generalized compliance matrix of part.
Design/methodology/approach
First, the form defects of parts may be decomposed into a linear combination of basic deviation fields, which are constructed by the eigen-decomposition of the structure stiffness of parts with ideal dimensions. Each basic deviation field is defined with a generalized compliance of part. Moreover, by analyzing the relationship between the basic deviation fields before and after assembling process, a new sensitive matrix is obtained in which each value expresses the correlation of a basic deviation field between the parts and the assembly.
Findings
This model may solve the deviation propagation problems of compliant assembly with considering form defects. Here, one case is used to illustrate the deviation propagation in the assembly process. The results indicate that the proposed method has higher accuracy than the method of influence coefficient when the entire deviation fields of parts are considered. Moreover, the numerical results with the proposed method basically agree with the experimental measurements.
Research limitations/implications
Owing to the hypothesis of linear superposition of basic deviation fields, the research in this paper is limited to the parts with linear elastic deformation. However, the entire form defects of parts are considered rather than the deviations of the local feature points. It may be extended to analyze the three-dimensional deviations of complex thin-walled parts.
Originality/value
A deviation propagation model considering parts form defects is developed to achieve more accurate predictions of assembly deviation by using the basic deviation fields.
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Haidong Yu, Chunzhang Zhao, Bin Zheng and Hao Wang
Thin-walled structures inevitably always have manufacturing deviations, which affects the assembly quality of mechanical products. The assembly quality directly determines the…
Abstract
Purpose
Thin-walled structures inevitably always have manufacturing deviations, which affects the assembly quality of mechanical products. The assembly quality directly determines the performances, reliability and service life of the products. To achieve the automatic assembly of large-scale thin-walled structures, the sizing force of the structures with deviations should be calculated, and its assembling ability should be studied before assembly process. The purpose of this study is to establish a precise model to describe the deviations of structures and to study the variation propagation during assembly process.
Design/methodology/approach
Curved thin-walled structures are modeled by using the shell element via the absolute nodal coordinate formulation. Two typical deviation modes of the structure are defined. The generalized elastic force of shell elements with anisotropic materials is deduced based on a continuum mechanics approach to account for the geometric non-linearity. The quasi-static method is introduced to describe the assembly process. The effects of the deviation forms, geometrical parameters of the thin-walled structures and material properties on assembly quality are investigated numerically.
Findings
The geometric non-linearity of structure and anisotropy of materials strongly affect the variation propagation and the assembly quality. The transformation and accumulation effects of the deviations are apparent in the multiple assembly process. The constraints on the structures during assembly can reduce assembly deviation.
Originality/value
The plate element via the absolute nodal coordinate formulation is first introduced to the variation propagation analysis. Two typical shape deviation modes are defined. The elastic force of structures with anisotropic materials is deduced. The variation propagation during the assembly of structures with various geometrical and material parameters is investigated.
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Abstract
Purpose
This paper aims to develop an optimization model to enhance pipeline assembly performance. It focuses on predicting the pipeline’s assembly pose while ensuring compliance with clamp constraints.
Design/methodology/approach
The assembly pose of the pipeline is quantitatively assessed by a proposed indicator based on joint defects. The assembly interference between the pipeline and assembly boundary is characterized quantitatively. Subsequently, an analytical mapping relationship is established between the assembly pose and assembly interference. A digital fitting model, along with a novel indicator, is established to discern the fit between the pipeline and clamp. Using the proposed indicators as the optimization objective and penalty term, an optimization model is established to predict the assembly pose based on the reinforced particle swarm optimization, incorporating a proposed adaptive inertia weight.
Findings
The optimization model demonstrates robust search capability and rapid convergence, effectively minimizing joint defects while adhering to clamp constraints. This leads to enhanced pipeline assembly efficiency and the achievement of a one-time assembly process.
Originality/value
The offset of the assembly boundary and imperfections in pipeline manufacturing may lead to joint defects during pipeline assembly, as well as failure in the fit between the pipeline and clamp. The assembly pose predicted by the proposed optimization model can effectively reduce the joint defects and satisfy clamp constraints. The efficiency of pipeline modification and assembly has been significantly enhanced.
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Bifu Xiong, Siliang He, Jinguo Ge, Quantong Li, Chuan Hu, Haidong Yan and Yu-An Shen
This paper aims to examine the effects of bonding temperature, bonding time, bonding pressure and the presence of a Pt catalyst on the bonding strength of Cu/SB/P-Cu/SB/Cu joints…
Abstract
Purpose
This paper aims to examine the effects of bonding temperature, bonding time, bonding pressure and the presence of a Pt catalyst on the bonding strength of Cu/SB/P-Cu/SB/Cu joints by transient liquid phase bonding (TLPB).
Design/methodology/approach
TLPB is promising to assemble die-attaching packaging for power devices. In this study, porous Cu (P-Cu) foil with a distinctive porous structure and Sn-58Bi solder (SB) serve as the bonding materials for TLPB under a formic acid atmosphere (FA). The high surface area of P-Cu enables efficient diffusion of the liquid phase of SB, stimulating the wetting, spreading and formation of intermetallic compounds (IMCs).
Findings
The higher bonding temperature decreased strength due to the coarsening of IMCs. The longer bonding time reduced the bonding strength owing to the coarsened Bi and thickened IMC. Applying optimal bonding pressure improved bonding strength, whereas excessive pressure caused damage. The presence of a Pt catalyst enhanced bonding efficiency and strength by facilitating reduction–oxidation reactions and oxide film removal.
Originality/value
Overall, this study demonstrates the feasibility of low-temperature TLPB for Cu/SB/P-Cu/SB/Cu joints and provides insights into optimizing bonding strength for the interconnecting materials in the applications of power devices.
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Jiawei Xu, Baofeng Zhang, Jianjun Lu, Yubing Yu, Haidong Chen and Jie Zhou
The importance of the agri-food supply chain in both food production and distribution has made the issue of its development a critical concern. Based on configuration theory and…
Abstract
Purpose
The importance of the agri-food supply chain in both food production and distribution has made the issue of its development a critical concern. Based on configuration theory and congruence theory, this research investigates the complex impact of supply chain concentration on financial growth in agri-food supply chains.
Design/methodology/approach
The cluster analysis and response surface methodology are employed to analyse the data collected from 207 Chinese agri-food companies from 2010 to 2022.
Findings
The results indicate that different combination patterns of supply chain concentration can lead to different levels of financial growth. We discover that congruent supplier and customer concentration is beneficial for companies’ financial growth. This impact is more pronounced when the company is in the agricultural production stage of agri-food supply chains. Post-hoc analysis indicates that there exists an inverted U-shaped relationship between the overall levels of supply chain concentration and financial growth.
Practical implications
Our research uncovers the complex interplay between supply chain base and financial outcomes, thereby revealing significant ramifications for agri-food supply chain managers to optimise their strategies for exceptional financial growth.
Originality/value
This study proposes a combined approach of cluster analysis and response surface analysis for analysing configuration issues in supply chain management.
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The purpose of this paper is to explore the relationship between firm size, the nature of ownership and corporate social responsibility (CSR) performance in China and to figure…
Abstract
Purpose
The purpose of this paper is to explore the relationship between firm size, the nature of ownership and corporate social responsibility (CSR) performance in China and to figure out the reason that state-owned enterprises (SOEs) usually perform better in CSR activities than private enterprises.
Design/methodology/approach
The authors conducted two studies of CSR in China. In the first study, the authors developed and assessed a CSR measure; second study was to investigate the difference of CSR behavioral performance between SOEs and private enterprises.
Findings
The authors found that the differences in CSR performances between SOEs and private enterprises were not caused by the nature of ownership as most Chinese scholars used to believe. Actually, the differences came from the differences of firm size, which had been ignored in prior studies on factors influencing CSR performance. The size of SOEs is usually much larger than private enterprises, and larger enterprises often perform better in the field of CSR. In a word, the size rather than the nature of ownership is the main reason that CSR performances of SOEs are better than private enterprises.
Originality/value
Though many papers in China suggested that SOEs performed much better than private enterprises in CSR activities, the authors proved that this belief was a misunderstanding. It was found that SOEs were usually larger than private enterprises, which might have confused their efforts to find the real reason that SOEs and private enterprises perform differently in CSR. The authors also developed a measuring tool of CSR based on the Stakeholder Theory, which would be a new measurement tool for future studies, especially for emerging market economies and unlisted companies.
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Lini Zhang, Haidong Zhao and Brenda Cude
This study, which is based on the extended hierarchy of effects (HOE) model, aims to examine whether social media interactions with one or more luxury brands can affect consumers'…
Abstract
Purpose
This study, which is based on the extended hierarchy of effects (HOE) model, aims to examine whether social media interactions with one or more luxury brands can affect consumers' knowledge of, affection for and purchases of as well as loyalty to luxury fashion brands as a category.
Design/methodology/approach
SoJump (a leading data collection company in China) launched an online survey to collect data from Chinese luxury fashion brand consumers. Structural equation modeling (SEM) was conducted to analyze data from the random sample of 308 Chinese luxury fashion brand consumers.
Findings
The findings of this study demonstrated that social media interaction had direct positive influences on three stages of the luxury fashion brand decision-making process – knowledge, affection and loyalty – but not purchases. The results also empirically confirmed that consumers' response to social media interaction follows the cognition-affect-conation sequential process presented in the HOE model.
Practical implications
This study not only provides a new perspective for researchers to investigate the impacts of interactive social media marketing on purchase decision-making in the luxury fashion brand category but also underpins the importance of building interactive alliances for luxury brands to increase consumers' knowledge of, affection for, purchases in and loyalty to the luxury fashion brand category.
Originality/value
This study is among the first to investigate whether social media interactions with luxury fashion brands as a category influence consumers' knowledge of, affection for and loyalty to that category. In addition, this study is the first attempt to explore whether social media interactions can directly influence consumers' luxury fashion brand purchases.