Abstract: Compared to traditionally-used metal materials, the structural parameters of glass fiber reinforced polymer (GFRP) composites have a large variation. The design parameters taken from the average values obtained from the structural test are thus not reliable. Therefore, investigations on mechanical properties of GFRP composites became increasingly important in their structural design. The strength values treated using statistical data should be used for design. The goal of this paper was to give a brief overview of the two methods for calculating A/B-basis values of GFRP composites, and to compare the accuracy of the two methods. The influential factors which affect the structural parameters of GFRP composites were also elaborated. The results show that the accuracy of the A/B-basis values improves with increasing the sample size; the use of the normal distribution leads to higher B-basis values than the use of the Weibull distribution. In addition, the conservation rate of the B-basis values reduces as the coefficient of variation of the samples becomes larger.

Key words: composite materials, glass fiber, A/B-basis, normal distribution, coefficient of variation