Identification of elastic constants for orthotropic materials from a structural test

• Published in: Computers and geotechnics Vol. 30; no. 7; pp. 571 - 577
• Main Authors: Shin, H.S., Pande, G.N.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.01.2003; Elsevier
• Subjects: Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Engineering geology; Exact sciences and technology; NNCM; Orthotropic; Vertical loads; Orthotropic; Vertical loads; NNCM; anisotropic materials; finite element analysis; elastic constants; methodology; neural networks
• ISSN: 0266-352X; 1873-7633
• DOI: 10.1016/S0266-352X(03)00062-4

In this paper, a new methodology for identifying numerous elastic parameters of any orthotropic material from a single structural test is presented. The state of stress in the tested structure (sample with non-uniform stress field) is admittedly complex and different points in it follow widely different stress paths. However, it has recently been shown that data of displacements at several points on the sample can be used to train a neural network embedded in a finite element code. The constitutive matrix resulting from the trained neural network based constitutive model (NNCM) is compared with the conventional constitutive matrix for an orthotropic material to determine the nine independent elastic constants. In order to demonstrate the methodology, test configuration of a panel of anisotropic material having a circular cavity at its centre and undergoing incremental vertical loads is adopted. Data of monitored displacements at several points needed to validate the methodology are obtained from a three-dimensional elastic finite element analysis assuming a set of orthotropic elastic constants for the material of the model. The elastic constants inferred from the trained NNCM are compared to those used for generating the load-deformation data. A very good agreement is noted.