Study on static and dynamic characteristics of nettle-polyester composite micro lathe bed

摘要

Nowadays, natural fibre-reinforced composites find applications in almost all engineering fields. This work is an attempt to realise improvement in dynamic characteristics of micro lathe bed using Himalayan nettle (Girardinia heterophylla) polyester (NP) composite as an alternate material. In order to study and validate the improvements envisaged, a cast iron micro lathe bed is considered as reference. Numerical (FE) model of the cast iron micro lathe bed was developed and validated through experimental static and modal analysis. Finite element analysis of the micro lathe bed with the existing cast iron material as well as with nettle-polyester composite as alternate material was also carried out using worst case cutting forces, and based on the relative performances, the need for form design modification for the proposed material was identified. To enhance the bending and torsional stiffness of the nettle-polyester composite lathe bed, various cross sections and rib configurations were studied and the best among them was identified and the same was implemented in the nettle-polyester composite micro lathe bed design. Finite element analysis of the newly designed nettle-polyester composite micro lathe bed was performed and the improvements in dynamic characteristics were evaluated. The newly designed nettle-polyester composite micro lathe bed was fabricated and the predicted enhancement in static and dynamic characteristics was verified experimentally. The studies indicated that nettle-polyester composite could be considered as a suitable alternate to cast iron structures in machine tools.