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When bending a large diameter thin-walled tube, the thickn ess of outer side wall will reduce greatly, which leads to a decrease of structural strength of the tube. To solve this problem, this paper investigated the deformation principles of an eccentric tube in the rotary draw bending process, trying to find a way to reduce the wall thickness difference between inner and outer diameters.

An finite element model is established for analyzing the deformation of an eccentric tube in rotary draw bending process. The wall thickness distribution of the formed pipe was analyzed along the axis and diameter, respectively.

It is found that there exists an optimal eccentricity between the inner and outer circle center of the tube cross-section. If the eccentricity of the tube is chosen properly, it is possible to get a bent tube with equal thickness of inner and outer side walls. In addition, it is also found the optimal eccentricity on the cross-section can be influenced by bending radius, wall thickness, diameter and bending angle. The optimal eccentricity increases greatly with the decreasing of bending radius, the increase of outer diameter and the increase of wall thickness. The influence of bending angle on the optimal eccentricity can be divided into two situations. When the bending angle is small, the optimal eccentricity increases with the increase of bending angle. When the bending angle exceeds a certain value, the pipe enters a stable forming state. The optimal eccentricity of the stable forming region does not change with the bending angle.

Such a research is beneficial for reducing the thickness difference between inner and outer side walls in the rotary draw bending process.

When manufacturing an arc-shaped tube product using push bending process, the transition zone and outfeed zone will inevitably occur. Transition zone and outfeed zone are caused by the kinematical motion of mobile tools. The existence of transition zone and outfeed zone will lead to a big deviation between the forming product and desired shape. To improve the forming quality of arc-shaped products in push bending, the transition zone and outfeed zone are investigated in this paper.

A piecewise function is used to describe the bending characteristics along bending line, in which a series of vibration parameters are extracted and considered as control values.

The new strategy is helpful for finding the relationship between tools motion and curvature distribution and improving the bending lines design procedure in flexible push bending.

The new strategy is helpful for finding the relationship between tools motion and curvature distribution and improving the bending lines design procedure in flexible push bending.

This study empirically investigates the role of product market competition and mature-stage firm life cycle on the relation between corporate social responsibility (CSR) and market performance in an emerging market context – Malaysia.

The authors construct a comprehensive CSR index toward the economy, environment and society (EES) and apply both Ordinary Least Squares (OLS) and Two-Stage Least Squares (2SLS) instrumental variables (IV) approaches to test the hypotheses of the study.

The authors find that EES-based CSR generally enhances firms' market performance; however, the level of product market competition undermines the market performance of socially and economically responsible firms. In addition, the study results indicate that mature-stage firm life cycle with more involvement in CSR activities shows better market performance. However, the endogeneity check of CSR suggests that both CSR and mature-stage firms are mutually exclusive in influencing market performance. The study findings are robust to alternative measures and different identifications of high and low default risk situations of sample firms.

This study carries practical policy implications for the listed firms, regulators and stakeholders in general. For example, regulatory bodies may promote greater involvement in CSR activities by listed companies in the Malaysian stock market. Investors and other market participants should be aware of factors influencing socially responsible firms' market performance such as the corporate life cycle and the level of competition in product markets.

This research work responds to the call of regulatory bodies in Malaysia at a time when the Malaysian economy is under threat of environmental distraction practices by the palm oil industry and import ban by the largest export market, i.e. the European Union by 2030. The study also contributes to the theoretical literature by refining the moderating role of product market competition and mature-stage life cycle on the relationship between CSR and market performance from the perspectives of resource-based and stakeholder theories in emerging economy settings.