Fracture behaviour of long fibre reinforced thermoplastics

In order to investigate the influence of void content on the fracture behaviour of carbon fiber reinforced polypropylene (CF/PP), we investigated the relationship between the mechanical properties of carbon fiber reinforced thermoplastics and their void content using CF/PP prepreg sheet and partially impregnated sheet. Two types of flexural properties of cross-ply (CP) plates and chopped carbon fiber tape reinforced thermoplastic (CTT) plates with different void contents were measured by three-point bending tests. The flexural strength of CP specimens decreased drastically when their void content became higher than 1%, whereas the flexural strength of the CTT specimens decreased gradually with an increase in void content. Un-impregnated regions in the composites resulted in small dotted defects under loading conditions, although they were only found on the tape along the longitudinal direction in the case of CTT. In addition, a larger number of defects was observed on CP and CTT specimens with lower strengths. Therefore, cyclic loading tests were conducted to observe flexural fracture behaviour in more detail to elucidate the reason behind voids causing a decrease in strength. During these tests, the dotted defects in the CP specimens were shown to be connected along the in-plane transverse direction, while those in the CTT specimen propagated along the second layered tape.

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The development toward the realization of sustainable carbon fiber-reinforced thermoplastics

Carbon ◽

10.1016/j.carbon.2021.01.080 ◽

2021 ◽

Vol 175 ◽

pp. 612-613

Author(s):

Toshihira Irisawa

Keyword(s):

Carbon Fiber ◽

Fiber Reinforced ◽

Carbon Fiber Reinforced ◽

Reinforced Thermoplastics ◽

Fiber Reinforced Thermoplastics

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Mesoscale Modelling of Concretes Subjected to Triaxial Loadings: Mechanical Properties and Fracture Behaviour

Materials ◽

10.3390/ma14051099 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1099

Author(s):

Qingqing Chen ◽

Yuhang Zhang ◽

Tingting Zhao ◽

Zhiyong Wang ◽

Zhihua Wang

Keyword(s):

Mechanical Properties ◽

Tensile Stress ◽

Failure Criterion ◽

Mesoscale Model ◽

Fracture Behaviour ◽

Descent Method ◽

Triaxial Stress ◽

Gradient Descent Method ◽

Stress States ◽

Shear Failures

The mechanical properties and fracture behaviour of concretes under different triaxial stress states were investigated based on a 3D mesoscale model. The quasistatic triaxial loadings, namely, compression–compression–compression (C–C–C), compression–tension–tension (C–T–T) and compression–compression–tension (C–C–T), were simulated using an implicit solver. The mesoscopic modelling with good robustness gave reliable and detailed damage evolution processes under different triaxial stress states. The lateral tensile stress significantly influenced the multiaxial mechanical behaviour of the concretes, accelerating the concrete failure. With low lateral pressures or tensile stress, axial cleavage was the main failure mode of the specimens. Furthermore, the concretes presented shear failures under medium lateral pressures. The concretes experienced a transition from brittle fracture to plastic failure under high lateral pressures. The Ottosen parameters were modified by the gradient descent method and then the failure criterion of the concretes in the principal stress space was given. The failure criterion could describe the strength characteristics of concrete materials well by being fitted with experimental data under different triaxial stress states.

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Mixed-Mode Fracture Behaviour of Semicircular Bend Shale with Bedding Layer

Arabian Journal for Science and Engineering ◽

10.1007/s13369-021-05376-2 ◽

2021 ◽

Author(s):

Yu Suo ◽

Zhixi Chen ◽

Sheik Rahman

Keyword(s):

Mixed Mode ◽

Fracture Behaviour ◽

Mixed Mode Fracture ◽

Mode Fracture

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Application of Glass Fiber and Carbon Fiber-Reinforced Thermoplastics in Face Guards

Polymers ◽

10.3390/polym13010018 ◽

2020 ◽

Vol 13 (1) ◽

pp. 18

Author(s):

Takahiro Wada ◽

Hiroshi Churei ◽

Mako Yokose ◽

Naohiko Iwasaki ◽

Hidekazu Takahashi ◽

...

Keyword(s):

Carbon Fiber ◽

Glass Fiber ◽

Impact Testing ◽

Fiber Reinforced ◽

Shock Absorption ◽

Glass Fiber Reinforced ◽

Field Of Vision ◽

Commercial Glass ◽

Carbon Fiber Reinforced ◽

Reinforced Thermoplastics

Face guards (FGs) are protectors that allow for the rapid and safe return of athletes who are to play after sustaining traumatic facial injuries and orbital fractures. Current FGs require significant thickness to achieve sufficient shock absorption abilities. However, their weight and thickness render the FGs uncomfortable and reduce the field of vision of the athlete, thus hindering their performance. Therefore, thin and lightweight FGs are required. We fabricated FGs using commercial glass fiber-reinforced thermoplastic (GFRTP) and carbon fiber-reinforced thermoplastic (CFRTP) resins to achieve these requirements and investigated their shock absorption abilities through impact testing. The results showed that an FG composed of CFRTP is thinner and lighter than a conventional FG and has sufficient shock absorption ability. The fabrication method of an FG comprising CFRTP is similar to the conventional method. FGs composed of commercial FRTPs exhibit adequate shock absorption abilities and are thinner and lower in weight as compared to conventional FGs.

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