On the importance of material and shape choice during upgrade of servo-hydraulic test rig for performing cyclic tests at extreme temperatures

Upgrade of existing test equipment with new mechanical components requires validation of the new setup. This study presents a concept and manufacturing of an additional mounting interface for performance of cyclic tests at extreme temperatures using an existing servo-hydraulic test rig originally designed for cyclic tests in a narrower temperature range around the room temperature. The material choice to ensure the structural integrity has played a major role in this study. The basis for the upgrade process were existing mounting clamps for specimens of circular cross-sections and existing temperature chamber. The final design of the interface consists of three sections each having a specific mechanical function. The base of the interface is fixed into the existing mounting clamps via mounting rods and ensures a rigid connection between the existing mounting clamps and the interface. A flexible middle section ensures the prescribed mounting force to clamp the specimens. The top section provides again a rigid frame for mounting the specimens. A structural analysis using finite element method has shown suitable compliance of the mounting interface for the performance of cyclic tests on aluminium alloys. Experimental verification using aluminium alloy Al2030 with six variable thermal and mechanical load histories has confirmed the simulation results.