Non linear finite element simulation of complex bulge forming processes

Bulge forming is a manufacturing process that is becoming increasingly important as a technology that can be used to produce seamless, lightweight and near-net-shape industrial components. The process is being increasingly applied in the automotive and aerospace industries where the demands for increased structural strength and decreased vehicle weight make it a very attractive manufacturing method. This work is concerned with increasing knowledge of the deformation mechanisms during bulge forming processes using numerical simulation. A number of complex bulge forming operations which have not been satisfactorily analysed in published research were identified and subsequently analysed using commercial finite element software. A non-linear explicit solution method was used in each case. The processes chosen for simulation were: hydraulic bulge forming of cross joints, bulge forming using a solid bulging medium, bulge forming of bimetallic tubes and the behaviour of the die during these bulge forming processes. In each case a number of process parameters were varied and their effect on the process identified. Where possible the finite element results were validated against results from experimental trials. It was found that the simulations predicted the experimental results with accuracy, thus indicating that the models developed here can be used with confidence to predict the behaviour of bulge forming operations. From the results of the finite element simulations it was concluded that when designing processes to bulge form cross joint components that compressive axial loading should be used in conjunction with pressure loading where possible, friction between the die and workpiece should be kept to a minimum where maximum branch height is required and greater tube thickness should be used when seeking to reduce stress and thinning behaviour in the formed component. The results also indicate that, where possible a solid bulging medium should be used as it results in much more favorable forming conditions, which can allow the realisation of greater branch heights. The simulations of bulge forming of bimetallic tubes showed that the relative thickness of the two metal layers has a significant effect on the shape of the final component. It was also found that varying the relative strength of the two metallic layers had a significant effect on the branch height obtained. The development of stress in the die during various bulge forming process was detailed at various stages during the process. It was found that generally a stress concentration moves towards the die bend as the process progresses. The effect of using different die materials was examined and it was concluded that certain materials are unsuitable for use as die materials due to the fact that their yield stress is exceeded during the forming process

Has the introduction of “Project Maths” at post-primary level affected the attitudes of first-year higher education engineering students in Ireland?

Mathematics is increasingly a focus of educational studies nationally and internationally, due to the growing need of mathematical skills in today’s technological, economical, and industrial world (European Commission 2011, Conway and Sloane 2005). It is widely known that mathematics is a core subject for science and engineering disciplines. As Project Maths was implemented on a phased basis over a four-year period, our study is directed upon testing the mathematical skills and investigating first year engineering students' attitudes towards mathematics over the course of the implementation. In this paper, we give a detailed overview of the results of a pilot attitudinal survey conducted in 2012 on a cohort of students who studied phase one of Project Maths. Overall, the results show quite a negative attitude towards mathematics, a fact that is naturally of concern among a cohort of engineering students who will rely heavily upon mathematics for the duration of their studies and beyond. Possible reasons for these attitudes will be further investigated in the following years, along with comparisons as to whether there are any improvements in students' mathematical skills and attitudes evident in the data we collect

The re-emergence of the 'black spectre': minority professional associations in the post-Macpherson era

This article reflects on the forging of a collective black identity among professionals working within the criminal justice field in the aftermath of the Macpherson Report (1999). Drawing on interviews with the Chairpersons of 'black' and 'Asian' professional associations, it describes the familiar tensions associated with mobilizing against racism and discrimination in the workplace. These include the viability of an inclusive black political position and the challenge of 'fighting from within' or being a 'critical friend' of criminal justice services. The political backdrop is one in which the policy goal of eliminating 'institutional racism' has given way to a discourse of 'promoting race equality and embracing diversity'. Despite the obstacles, these professional associations provide a safe and supportive network for members which is grounded in a powerful, shared history of occupational racism