DEHAN ENGINEERING NUMERICS

ENGINEERING APPLICATIONS OF LAYERED COMPOSITES OR LAMINATES ARE VERY IMPORTANT AND DIVERSE. INTERLAYER CRACKSOR DELAMINATIONS IS ONE OF THE MAJOR REASONS OF COMPOSITE STRUCTURAL FAILURE. DELAMINATIONS MAY CAUSE CONSIDERABLE DEGRADATION OF STIFFNESS AND STRENGTH OF COMPOSITE STRUCTURES. THIS PHENOMENON HAS RECEIVED CONSIDERABLE ATTENTION IN RECENT YEARS. BUT, TO ACHIEVE A DEEPER INSIGHT INTO THE PROBLEM, SEVERAL ISSUES NEED TO BE FURTHER ADDRESSED. THESE STUDIES SHOULD INCLUDE THEORETICAL ISSUES AND MODELLING, AS WELL AS ANALYTICAL NUMERICAL AND EXPERIMENTAL INVESTIGATIONS OF BOTH BASIC AND APPLIED NATURES. THIS PROJECT FOCUSES ON THE PROPAGATION OF AN EXISTING DELAMINATION IN A LAYERED COMPOSITE. A NEW MECHANICS MODEL WILL BE DEVELOPED, WHICH WILL ADDRESS THE MAIN FEATURES OF A DELAMINATED PLATE AND LEAD TO AN EFFICIENT COMPUTATIONAL METHOD BASED ON THE FINITE ELEMENT METHOD. THE BEHAVIORS OF STRUCTURES DURING DELAMINATION PROPAGATION WILL BE SIMULATED FOR THE CASES OF STEADY LOADING AND CYCLICLOADING. THE EFFECTS OF DELAMINATION SHAPES, SIZES AND LOCATIONS WILL BE ANALYZED. SEVERAL EXPERIMENTS WILL BE PERFORMED TO UNDERSTAND THE MAIN FEATURES OF DELAMINATION PROPAGATION AND TO VERIFY THE THEORETICAL MODEL AND COMPUTATIONAL RESEARCH. THE RESULTS OBTAINED FROM THIS RESEARCH ARE EXPECTED TO BE VERY USEFUL FOR THE NON-DESTRUCTIVE EVALUATION OF COMPOSITE STRUCTURES AND THE MANUFACTURE OF COMPOSITE MATERIALS.