Spring-in behavior of woven carbon fiber/polycarbonate thermoplastic composites

Abstract

The spring-in behavior of woven carbon fiber/polycarbonate thermoplastic composite is investigated by both the experiment and simulation ways. These thermoplastic composite plates are thermoformed into V-shaped structures, and the final bending angle is measured after demolding. In the finite element simulation to describe the thermoforming and spring-in behavior of the composite, the discrete approach is adopted to simulate the behavior of woven carbon fabric and combined with a resin model. The results from both the experiment and the simulation indicate the spring-in behavior of this thermoplastic composite. For [(±45)]6 blanks, the spring-in angle is around 2.60° for a 60-degree V-shape and around 1.72° for a 90-degree V-shape. For [(0/90)]6 blanks, the spring-in angle is around 2.38° and 1.19° for 60-degree and 90-degree V-shapes, respectively. The [(±45)]6 blank always has a slightly higher spring-in angle than the [(0/90)]6 blank, even though the difference is small. The finite element results show 6% to 12% differences with the experimental values if the spring-in angle is used, and the error is less than 0.6% when the bending angle is compared. By using the present finite element analysis, the results indicate that the stacking sequence could have an evident effect on the spring-in angle, and symmetric laminates have less spring-in effect as compared to their unsymmetric counterparts.

An Overview of Angle Deviations of Fiber-Reinforced Polymer Composite Angular Laminates

“…Han et al [42] indicated significant spring-in values from 2.087 • to 3.431 • for carbon fiber-reinforced PPS laminate thermoformed into a 92-degree V-shape as the forming temperature of 320 • C and the tool temperature changed from 80 • C to 230 • C. For symmetrical laminates, the lay-up sequence, either [[(0/90)/(±45)] 2 ] S or [[(±45)/(0/90)] 2 ] S , had little effect on the spring-in value. Hwang et al [43] investigated the angle deviation of woven carbon fiber/polycarbonate composites after thermoforming and found that the spring-in angle was around 2.60 • for a 60 • V-shape and around 1.72 • for a 90 • V-shape for [(±45)] 6 blanks. The [(0/90)] 6 blank had a slightly higher spring-in angle than the previous blanks.…”

“…For symmetrical laminates, the lay-up sequence, either or , had little effect on the spring-in value. Hwang et al [ 43 ] investigated the angle deviation of woven carbon fiber/polycarbonate composites after thermoforming and found that the spring-in angle was around 2.60° for a 60° V-shape and around 1.72° for a 90° V-shape for blanks. The blank had a slightly higher spring-in angle than the previous blanks.…”