The effect of temperature on mechanical properties and failure behaviour of hybrid yarn textile-reinforced thermoplastics

et al. 2015

The charpy impact experiments on the 3D integrated woven spacer composites with six types of core heights are performed at room and liquid nitrogen temperatures (as low as -196 o C). Macro-fracture morphology and SEM micrographs are examined to understand the deformation and failure mechanism. The results show that the impact energy increase with the increase of the core height at both room and liquid nitrogen temperatures. Meanwhile, the impact properties at liquid nitrogen temperature have been improved significantly than that at room temperature. Moreover, at room temperature, the penetration fracture of the face sheets, the tearing and pulling out of the core fibers as well as the cracking of the matrix is the main damage and failure patterns. However, at liquid nitrogen temperature, the matrix crushing dominates the failure. Less fibers fracture and brittle fracture feature becomes more obvious. In addition, with the increase of the core heights, the damage of composites has been reduced significantly at room and liquid nitrogen temperatures.

Section: Failure Mechanism At Room Temperaturementioning

confidence: 99%

Experimental study on the charpy impact failure of 3D integrated woven spacer composite at room and liquid nitrogen temperature

Zhao

et al. 2015

“…The reason is because the mobility of the polymer chains within the resin matrix will be reduced and the molecules of polymer matrix are more closely compacted at liquid nitrogen temperature; At the same time, the transverse shrinkage of carbon fibers is smaller than that of resin matrix, the interface friction force is augmented and higher interface bond strength is attained, which improved significantly tensile properties of composites [23,24].…”

Section: Mechanical Propertiesmentioning

confidence: 99%

Mechanical response and failure of 3D MWK carbon/epoxy composites at cryogenic temperature

Duan

et al. 2015

Static tensile and bending experiments are conducted on 3D MWK carbon/epoxy composites with two types of fiber architecture at room and cryogenic temperature (low as -196 o C). Macro-Fracture morphology and SEM micrographs are examined to understand the deformation and failure mechanism. The results show that tensile stress vs. strain curves have linear elastic feature up to failure; while the load-deflection curves for composites with large fiber orientation angle have pronounced nonlinear and failure in steps. Meanwhile, tensile and bending properties at liquid nitrogen temperature have been improved significantly. Moreover, the properties can be affected greatly by the fiber architecture and these decrease with increasing fiber orientation angle at room and cryogenic temperatures. The results also show the damage and failure patterns of composites vary with the fiber architecture and temperature. The main failure for material A is 0 o fibers fracture and matrix cracking. The failure mechanism for material B is the delamination, 90 o /+45 o /-45 o fiber/matrix interface debonding and fibers tearing, as well as 0 o fibers' breakage. At cryogenic temperature, the matrix is solidified and the interfacial adhesion between fibers and matrix is enhanced significantly. However, the brittle failure becomes more obvious, more microcracks propagate and interpenetrate.

“…For material A, comparing the properties at room temperature with that at elevated temperatures of 55 o C, 75 o C and 100 o C, the bending strength is decreased by This is due to the fact that the mobility of polymer chains within the resin matrix will be increased and the molecules of polymer matrix are not closely compacted at elevated temperatures. At the same time, the matrix is getting softened and cracked at elevated temperatures, the interface friction force is reduced and weaker interface bond strength is attained, which has decreased the mechanical properties of composites significantly [23,24].…”

Section: Bending Strength and Bending Modulusmentioning

confidence: 99%

Experimental study on the bending properties and failure mechanism of 3D MWK composites at elevated temperatures

et al. 2015

This paper reports the effect of temperature on the bending properties and failure mechanism of 3D MWK (Multiaxial warp knitted) composites. Three-point bending experiments on composites with three fiber architectures were performed at four different temperatures. Then the effect of temperature on the load/deflection curves, bending strength and stiffness were analyzed. Macroscopic fracture morphology and SEM micrographs were also examined to understand the deformation and failure mechanism. The results show that the temperature has great impact on the bending properties of 3D MWK composites and the performance decreases significantly with the increase of the temperature. Meanwhile, the bending properties can be affected greatly by the fiber architecture and these decrease significantly with the increase of fiber orientation angle at room and elevated temperatures. Moreover, the damage and failure patterns of composites vary with the test temperature and fiber architecture. At room temperature, the composite exhibits brittle fracture feature and damages in the breakage and tearing of fibers. But at the higher temperature, the composite becomes more softened, cracked and plastic. It damages in fiber layer delaminating, matrix cracking and fiber/matrix interface debonding.