The safety-factor calibration of laminates for long-term applications: behavior model and reliability method

This paper presents a method for determining safety factors which must be t aken into account when designing laminates for longterm applications. The m ethod requires two steps: the first is a behavioral model able to predict t ime-dependent phenomena, and the second is a reliability method. The meso/m acro approach is used in the behavioral model. This paper presents a damage d elastoviscoplastic model able to predict the behavior of a layer made of a polymer reinforced with unidirectional fibers. This model requires a non- linear laminate theory which provides the response of laminate structures. The method for calibrating safety factors is based on the first-order relia bility method. A description of the behavioral model in this method is pres ented. Finally, as a working example, the design of filament-wound pipe for fluid transportation is presented. A functional criterion is introduced to prevent leakage. The effect of material parameters is analyzed. (C) 2001 E lsevier Science Ltd. All rights reserved.