Novel test method to determine shear properties of lattices: Test set-up and data analysis

Abstract

In order to determine shear response for lattices, relevant standards for other similar materials were studied. A V-notched beam shear test set-up was developed, including design of a fixture and a V-notched lattice specimen as well as determining test procedure and data analysis method. Followings are some of the considerations and features. Sufficient number of cells are required to obtain representative properties for a given lattice. The free-end condition for installation and gripping of the specimen on fixture arms guarantees loading in pure shear. The overall geometry and presence of a V-notch smooth the shear stress variation across the notch section. It was demonstrated that using Digital Image Correlation (DIC) method improves the accuracy of measured shear strain by removing the deformation of cells adjacent to the notch, as well as the deflection of fixture components. Following the proposed method, shear properties including shear chord modulus of elasticity, offset shear strength, and shear ultimate strength/strain can be determined. These data can be used for material specification, quality assurance, research and development, and structural design and analysis of lattices.