Fracture of Fiber-Reinforced Plastics

Fracture Mechanics Methods for Interface Bond Evaluations of Fiber-Reinforced Plastic/Wood Hybrid Composites... 

Favre J.P. (1977). Improving the fracture energy of carbon fiber reinforced plastics by delamination promoters. J. Mater. Sci. 12, 43-50. 

Fibre-reinforced plastic composites - Determination of mode I interlaminar fracture toughness, Gic, for unidirectiOTially reinforced materials Testing methods for interlaminar fracture toughness of carbon fiber reinforced plastics... 

Fiber-reinforced plastics are the most successful composite materials. In spite of the poor load-bearing ability of polymeric materials, excellent mechanical properties are achieved by using fiber architectures of glass and carbon hbers in a manner similar to the reinforcement of concrete with steel rods and frames. For example, toughened polymeric materials with dispersed rubber particles in a polymer matrix exhibit high fracture energy. In composite materials, introduction of secondary materials into the matrix can improve the mechanical properties considerably. 

Komai K, Minoshima K, Shiroshita S. Hygrothermal degradation and fracture process of advanced fiber-reinforced plastics. Mater Sci Eng 1991 A143 155-166. 

Nishikawa M, Okabe T and Takeda N (2009) Effect of the microstructure on the fracture mode of short-fiber reinforced plastic composites, J Solid Mech Mater Eng 3 998-1009. 

Figure 1.25 Influence of aging conditions on fiber-matrix adhesion in glass fiber-reinforced plastics scanning electron microscopic images of fracture surfaces (tensile test)...

The well-known S-N curves are - probably for historical reasons — the method most often used to describe fatigue behavior for fiber reinforced plastics. In this discontinuous (as defined in the previous section) procedure, the fatigue criterion is typically fracture, that is total failure of the test specimen. Statistic evaluation leads to statements regarding the probability of fracture P, Figure 1.65. 

In Table 4.12, the composite structure is stated for processing and testing of eight different glass fiber reinforced plastic laminates (EP, UP, VE). Their dynamic properties are listed in Table 4.13 [148]. With fiber contents (p ranging from 0.22 to 0.66%, tensile-fracture stresses (short-term) between 80 and 750 N/mm are achieved at fracture strains of 0.88 and 3.47%. 

The time-temperature dependence of the flexural constant strain-rate (CSR), creep, and fatigue strengths of various carbon fiber-reinforced plastics (CFRP) has been studied by McMurray et aV and Miyano et al. It was observed by Enyama et al that the fracture modes are almost identical for the above three types of loading over wide ranges of time and temperature. Similar results were also reported by Karayaka et al at room temperature. The literature survey indicates the validity of the two hypotheses for CFRP the same failure process and the same time-temperature superposition principle for CSR, creep, and fatigue failure. 

Figure 4.4 Comparison of (a) stiffness, (b) strength, and (c) fracture toughness for metals, technical ceramics, composites, and fiber-reinforced plastics with respect to those of bone. CF, carbon fiber GF, glass fiber PA 12, polyamide 12 PC, polycarbonate PE, polyethylene PEEK, poly ether ether ketone PLGA, poly(L-lactic-co-glycolic acid) PLEA, poly(L-lactic acid) PP, polypropylene PSU, polysulfone PTFE, polytetrafluoroethylene PUR, polyurethane.

Jansson, J.-F. Sundstrom, H., Creep and fracture initiation in fiber reinforced plastics. In Failure of Plastics, ed. W. Brostow R.D. Corneliussen. Hanser Publishers, Munich, 1986. 

---