Stress‐time superposition of creep data for polypropylene and coupled glass‐reinforced polypropylene

Abstract

Abstract Glass‐reinforced thermoplastics are being considered in many structural applications and fabricators require design information on these materials. Basic creep data are, in many cases, the most useful for design purposes. The work reported here concerns the development of methods of increasing our efficiency in generating creep data. The methods developed are applicable to polypropylene and coupled, glass‐reinforced polypropylene. A stress‐time superposition procedure has been found valid for extending creep data generated on coupled glass‐reinforced polypropylene at several glass levels and at temperatures of 23 and 80°C.