Failure mechanism of unidirectional basalt fiber‐reinforced polymer composites with pretension of fiber yarns

Abstract The pultrusion process has received increasing attention because of its high productivity, low cost, and good product quality. During the pultrusion process, the pulling and pretension force is a key factor to control the quality of the products. In this paper, the effect of the pretension force on the tensile strength of basalt fiber‐reinforced polymer (BFRP) composites was studied. The pretension force was controlled using different weights. Tensile tests were performed on the BFRP specimens and the microscopic analysis was examined by scanning electron microscopy. The results showed that the static tensile strength of specimens climbed up initially, followed by a decrease with the increase of pretension weights. Three microscopic changes under different pretension forces were found and discussed to explain the damage and failure mechanism. It is essential to optimize the pretension force to improve the strength quality for the pultrusion products of BFRP.