1. Department of Mechanical Engineering, University of Aveiro, 3810-193 Aveiro, Portugal
2. Centre for Mechanical Technology and Automation, 3810-193 Aveiro, Portugal
3. Department of Mathematics, University of Aveiro, 3810-193 Aveiro, Portugal
4. Center for Research and Development in Mathematics and Applications (CIDMA), 3810-193 Aveiro, Portugal