Static and Fatigue Strengths of a G40-800/5260 Carbon Fiber/Bismaleimide Composite Material at Room Temperature and 150°C

Abstract

The objective of this study was to investigate the static and fatigue strengths of a G40-800/5260 carbon fiber/bismaleimide composite material, a type of high temperature CFRP, at room temperature (RT) and 150°C and to evaluate the practicality of this material. The stacking sequence of the material is quasi-isotropic, 32 plies [+45/0/-45/90]4s. Static tensile and compressive tests were performed at RT and high temperatures for non-hole (NH) and open-hole (OH) specimens. In addition, the effectiveness of notched strength criteria was discussed on the basis of test results. Fatigue tests yielded the S-N relationships of OH specimens for three kinds of stress ratio R (=minimum stress/maximum stress), R=0.1 (tension), 10 (compression), and -1 (tension-compression) at RT and 150°C. This study laid emphasis on investigating the static and fatigue strengths at 150°C and the role of compression load repetition in tension-compression fatigue. Major findings are as follows. (1) Static NH and OH compressive strengths, OH compression fatigue strength, and OH tension-compression fatigue strength were temperature-dependent and classified as matrix-dominant properties. These fatigue strengths decreased with increasing load cycles. (2) An open hole greatly reduced static tensile and compressive strengths at both RT and 150°C. (3) The ratio of compression strength to tension strength under static or fatigue loading was fairly low for both NH and OH specimens at RT and 150°C, except for the case of NH static strength at RT. (4) The compression stress range mostly controlled fatigue lives in tension-compression fatigue tests at RT and 150°C. (5) The material tested showed no large static and fatigue strength reduction at 150°C except for NH compressive strength; however, it should be used with care when structures have open holes and encounter compression loading, especially at high temperatures.

G40-800/5260 Carbon Fiber/Bismaleimide Composite Material: High Temperature Characteristics of Static and Fatigue Strengths

“…Therefore, the numerical values presented in Table 3 are considered reasonable. The authors discussed the effect of an open hole on the static strength of CFRPs in detail based on theoretical formulae and test results (Shimokawa et al, 2008).…”

“…As for fatigue strength, Hirano only discussed rough S-N relationships of fatigue characteristics at RT as determined by axial tension, compression and tension-compression fatigue tests using a small number of test specimens. Under these circumstances, the authors systematically conducted static tests on NH and OH specimens and fatigue tests on OH specimens for a CF/BMI composite material with a quasi-isotropic layup at RT and high temperatures and discussed test results and the high-temperature practicality of this material (Shimokawa et al, 2008). In this chapter the authors introduce the major contents of their previous paper from a practical viewpoint.…”

Fatigue Analysis of Ti-55 Alloy Material for Multifunctional Surgical Instruments in Medical Engineering

“…4 to display the fatigue limit as a function of the mean stress. For a real structure, the Haigh diagram must be reduced, due to the fact that the design was not used in laboratory conditions, where disturbing factors appear, like surface irregularities, volume factor due to process and volume factor due to geometry [7]. Although the fatigue parameters were estimated only approximately, the predictive capability of the presented methodology seems quite satisfactory and welcome.…”

Investigation of the viscoelastic response of high temperature AS4‐12K/RP46 composites using a micromechanical approach

“…Another example of high temperature polyimide resins is Avimid K3B, which is a thermoplastic material used for supersonic transport aircrafts with an operating temperature of ∼180°C . Other thermoset and thermoplastic polyimide resins include R1–16, PETI‐5, and PIXA .…”