Servo-press thermoforming process of CF/PEEK pultruded rod head and damage behavior under head tensile loading

Abstract

In this study, a novel carbon fiber reinforced thermoplastics (CFRTP) rod head servo-press thermoforming apparatus using two servo-press units and a ring-type heater in the die was developed. The CFRTP rod head was thermoformed using carbon fiber reinforced polyetheretherketone (CF/PEEK) round rod prepared by thermal pultrusion process. Thermoforming force and displacement during CF/PEEK rod head thermoforming and die clamping force and displacement of the concave die of lower die were controlled individually and precisely by upper and lower servo-press units and were monitored during CF/PEEK rod head thermoforming. Using this apparatus, the shape, dimensions, and density of CF/PEEK rod heads were measured by varying the thermoforming force, head shape (Flat type or Rosette type) and head height, and fiber orientation of the round rod. And the damage behavior was investigated from the load-displacement behavior in head tensile test and cross-sectional images of the heads before and after the test. As a result of thermoforming Flat and Rosette type CF/PEEK rod heads, Rosette type CF/PEEK rod head was more reproducible in head forming. The results of thermoforming by varying the thermoforming force showed that there is an optimal load for the head thermoforming.

Keywords

• carbon fiber reinforced polyetheretherketone (cf/peek)
• rod head
• servo-press
• thermoforming
• damage behavior