An orthotropic plastic constitutive model for fiber-reinforced composite material, is developed, which is simple and efficient to be implemented into computer program for a predictive analysis procedure of composite laminates. An orthotropic initial yield criterion, as well as work-hardening model and subsequent yield surface are established that includes the effects of different yield strengths in each material direction, and between tension and compression. The current model is implemented into a computer code, which is Predictive Analysis for Composite Structures (PACS). The accuracy and efficiency of the anisotropic plastic constitutive model and the computer program PACS are verified by solving a number of various fiber-reinforced composite laminates. The comparisons of the numerical results to the experimental and other numerical results available in the literature indicate the validity and efficiency of the developed model.

ABSTRACT
 1. INTRODUCTION
 2. CONSTITUTIVE MODEL FOR ORTHOREOPICMATERIALS
  2.1 Elastic Constitutive Relationship
  2.2 Orthotropic Plasticity Theory
  2.3 Orthotropic Yield Criterion
  2.4 Evaluation of Interaction Term
 3. CONCLUSIONS
 References

• 이규세(선문대학교 토목공학과) | Gyu-Sei Yi