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Mario Carandente - Self Pierce Riveting

Professor Richard Dashwood – Academic Director, WMG
Dr Iain Masters – Senior Research Fellow, WMG

The following is an interview conducted with Mario and his supervisors for JLR's in-house magazine:

Can you explain your research and its importance to your sponsor company?

I’m working on the simulation of self-piercing rivets (SPR), using finite element analysis. Self-piercing riveting is the cold joining process used by Jaguar Land Rover (JLR) for the joining of the aluminium ‘body in white’. It is a very fast process, however there are some issues from an industrial point of view. What we are trying to do is to develop a tool to assess the quality of the SPR process to speed up the design processes and to enable more feasibility assessment to be provided.

The typical problem occurs with the ‘body in white’ stage – when a car’s sheet metal components have been joined together to form the body structure, but before moving parts or trims have been added. For the new Range Rover there are 18 different rivet types and 28 different dies that have to join 246 different material stacks.

Prof Dashwood:
In a manufacturing environment you want to have as few rivet combinations as possible as every time you change the rivet and die combination it adds time and effort. From an efficiency point of view you’d like one rivet and one die. But this is impossible.

So what is difficult now is to find out the right combination for each rivet gun, so we need to undertake extensive experimental work to establish the correct rivet and die combinations. We are developing a model to ascertain the joint quality attributes and joint quality parameters without physical experimental tests.

The variation of the rivets comes from different strengths, designs and lengths. The dies also have different geometries. The choice of the rivet/die combination is obviously dependent on the mechanical properties and thickness of the stack to be joined. I’m also looking at the temperature raising and friction generated during the riveting process.

Dr Masters:
By using the simulation tool we’ll be able to see which rivets we can use to achieve an acceptable join. It might not be optimised but it’s acceptable. That has a major benefit to the company as it means we can lower the stock of different rivets we carry.

As we’re bringing more products to market, we need these detailed models to predict how certain rivets will behave. Moving away from physical testing speeds up the whole process and saves money.

What is the relationship between the sponsor company, the Doctoral student and WMG? How does it work?

Professor Dashwood:
With all EngDs there’s an industrial supervisor as well as an academic supervisor. In this case, a lot of JLR employees are based on campus so the communication is really good. Mario gets a significant amount of time interacting with JLR without spending too much time away from the office here at WMG where a lot of interactions take place.

WMG supports me on all of the technical aspects of the project, whereas JLR provide me all of the background and the issues from an industrial point of view. This project is very important for JLR and the self-pierce riveting action will be the cold joining process for every vehicle in the foreseeable future.

Why an EngD?

The EngD gives you the skills to develop not only the research and development side of a project, but also the management and business skills required, as you have to not only deal with your sponsor company but you have to do some taught modules here in WMG. For example, business and management, entrepreneurship, and project planning, management and control.

Professor Dashwood:
I think the emphasis with an EngD is on training the individual, whereas with a PhD it is much about developing the research. On the EngD, by the time Mario is finished he can potentially be employed by Jaguar Land Rover. It’s a bit like an advanced graduate scheme.

One analogy would be to consider it an MBA for research and development. I have been on the programme for one year and it is a challenging programme. You have to deal with your sponsor company so you have to understand fully about the industrial issues affecting them and provide a solution. I also had the opportunity to present my findings to Paul Peterson, Manufacturing Director of Jaguar Land Rover, and several Chief Engineers like Mark White, so it’s been a fantastic experience.

Dr Masters:
The collaboration here is pretty important. We offer that very useful link between academia and industry so students coming through the programme have had the right exposure in a real working environment.

Professor Dashwood:
One of the beauties of the Engineering Doctorate is that it can be used as a way of getting skilled people into the organisation where there are skill shortages, while actually training them. We live in a country where we have become obsessed with the finance and service industries so it’s important that we keep engineers in engineering companies.

Mario Carandente

Mario and Supervisors