Resonant ultrasound spectroscopy measurement and modeling of additively manufactured octet truss lattice cubes

Abstract

Advancement of additive manufacturing technological readiness requires high throughput evaluation capabilities that can keep pace with the development of complex parts. Resonant ultrasound spectroscopy (RUS) is an acoustic technique that provides rapid holistic probing of a part by tracking fundamental mechanical resonance modes. In this work, the RUS responses of additively manufactured Ti-5553 octet truss lattice cubes were characterized using experimental measurements and three-dimensional finite element models. Varying percentages of missing struts were designed into the lattices as controlled defects and were verified using X-ray computed tomography. Experimental measurements of density and Young’s modulus were treated as input parameters in a homogenous anisotropic continuum model. The continuum model was compared with experimental RUS measurements, thus evaluating the potential for a simplified approximation of the octet truss lattice. [This work was supported by US DOE LLNL-LDRD 20-SI-001 and was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.]