Internal deformation measurement of 3D printing materials based on digital volume correlation method

Abstract

By using industrial CT equipment,the three-dimensional digital volume image of the specimen of the 3D printing material before and after the deformation was obtained, and then the internal three-dimensional displacement field and three-dimensional strain field of the specimen were calculated by using digital volume correlation (DVC),from which the internal deformation and damage evolution of the specimen under load were studied. By designing and fabricating an in-situ loading device with 1700 N tensile and compress loading capacity, and combining it with micro-nano CT equipment, the DVC method test device with in-situ loading and observation capability was established, and the highest imaging resolution is 10 μm. The results show that when the in-situ tensile test is carried out on the 3D printing aluminum alloy specimen prepared by the laser selective melting (SLM) process, and the full field displacement and strain data inside the specimen are obtained by the DVC method, the elastic modulus data measured from cloud image is in good agreement with the results of conventional test methods. It is proven that DVC is an effective method for measurements of internal displacement field and strain field.

Keywords

• digital volume correlation method
• internal deformation
• 3d printing material
• mechanical property
• <i>in-situ</i> loading