Abstract : An analytical model appropriate for the analysis and design of thick laminated composite media is presented. The model is based on the theoretical work of Chou, Carleone, and Hsu (1972) and predicts the effective three-dimensional thermo-mechanical properties and ultimate strength of thick laminated composite media under applied mechanical and thermal loadings. Various types of lamina constitutive models and lamina failure criteria (including progressive ply failure) have been incorporated in the analysis. A major result of this work is the codification of a three-dimensional laminated media model into a user-friendly computer program environment (LAM3D) for implementation as an engineering design tool for thick laminated composite structures. LAM3D predictions are validated with comparisons between results in the published literature and available experimental data. Several illustrative examples are presented to demonstrate the utility of the code for predicting the effective properties and ultimate strength of laminated composite media. This work represents an important step toward the development of a computationally efficient engineering tool which will significantly enhance the design and analysis capability for the development of a wide range thick composite structures currently being investigated for military and commercial applications. (MM)