Fixture for tensile samples

grabcad

The fixture is a design concept that can be used to roughly estimate if a fabricated/machined part has been made according to specifications. During mechanical testing, different specimen preparation is essential. However, checking every dimension of the fabricated/machined part is not ideal. For my submission, I used four tensile geometries based on ASTM E8 as an example to generate a fixture. Although, this workflow can be used to generate fixtures for any traditionally/additively manufactured part. The goal of the design was to easily check the dimensional accuracy of different parts.For the fixture generation, additive manufacturing would be ideal since the geometry of the parts varies from project to project. Also, for making the part lightweight (about a 25% reduction in weight), lattices were used. This would be difficult to make using traditional manufacturing processes. For the design process, the parts used as an example were designed in SolidWorks but the fixture itself was generated using nTopology. Although gyroid-based lattice designs are getting more attention, this design utilizes the square honeycomb lattice for simplicity. Additive manufacturing processes would be useful in this regard as well since a simple structure such as this would not create a thermal gradient or residual stresses during the part fabrication. Since high thermal gradient and residual stresses within the parts are detrimental to the part fabrication, this needs to be accounted for during the design as well.