AbstractDuring creep deformation many polymeric materials exhibit small cracklike zones, crazes. In the literature it is reported that crazing will not occur if the strain is kept under a critical value, specific for each material. This fact has importance in avoiding rupture. In this work a uniaxial theory is put forward that is based on a creep law describing the buildup of internal stress and on the Kachanov damage law. Crazing is here regarded to be a stage in the damage accumulation process, the final stage of which is rupture. Relations among the critical strain, the corresponding critical stress, and the minimum stress leading to creep rupture are derived. Some conditions that are necessary for the critical strain concept to work are formulated.
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