Design and Performance Evaluation of Modular Compliant Mechanisms

In this study, modular design for compliant stage using a parallelogram flexure module is proposed. The material of the proposed stages chosen is Aluminium alloy T6-6051 due to excellent phase stability, low internal stresses, low density etc. The stage is driven by a linear electromagnetic actuator i.e. voice coil actuator. The preliminary static structural analysis is used to determine the range of motion, stiffness by considering stress limitations. FEA results show a maximum range of motion up to 30mm without exceeding stress limit of 275 Mpa. The proposed mechanisms provide low stiffness in the degree of freedom directions and provide large stiffness in the degree of constraint direction.so it is adequately constrained. The stage provides high precision and repeatability with an increased range of motion, minimal parasitic motions (i.e.150 microns) and limited cross axes coupling

Computer Aided Design and Heat Transfer Analysis of Handguard of a Gun

The study presents thermal analysis of the handguard of a gun using finite elements as well as finite differences. The thermal loading corresponds to continuous firing of 300 rounds for 600s follwed by an inactive period of 300s. The maximum barrel temperature recorded was around 300 degree celsius. Three different handguard materials namely Ryton-4 PEEK-450G and PEI were tested. The effectiveness of a reflector shield located between the barrel and the handguard was studied. Two major results that emerged from the study are:(1)Ryton-4 gives the lowest temperature rise among the three materials studied and (ii)The reflector shield is crucial for maintaining the handguard temperature within limits. Spatial and temporal variation of temperature are qualitatively similar in the two numerical models. Owing to certain factors the finite element predictions for the handguard are on the higher side compared to finite differences. The maximum handguard temperatures as determined in the present model including the reflector are summarized in the Table 1. It is clear that the Ryton-4 as the handguard material can be considered as most desirable