1. School of Mechanical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
2. School of Mechanical Engineering, University of Birmingham, Edgbaston B15 2TT, Birmingham, UK
3. The Manufacturing Technology Centre, Ltd., Pilot Way, Ansty Park, Coventry CV7 9JU, UK
4. School of Mechanical Engineering, University of Birmingham, Egbaston B15 2TT, Birmingham, UK