Masaya Miura

Mixed-mode I/III fatigue delamination growth in woven glass/epoxy composite laminates at cryogenic temperatures

This work deals with the delamination growth behavior in woven glass fiber reinforced polymer (GFRP) composite laminates under mixed-mode I/III fatigue loading at cryogenic temperatures. Fatigue delamination tests were carried out with eight-point bending plate (8PBP) specimens at room temperature, liquid nitrogen temperature (77 K), and liquid helium temperature (4 K), and the delamination growth rate data were expressed in terms of the energy release rate range during fatigue loading. The energy release rate was calculated using the three-dimensional finite element method. Moreover, the fracture surface characteristics of the woven GFRP laminates under mixed-mode I/III fatigue loading were examined by scanning electron microscopy (SEM).

Cryogenic Interlaminar Fracture Properties of Woven Glass/Epoxy Composite Laminates Under Mixed-Mode I/III Loading Conditions

We characterize the combined Mode I and Mode III delamination fracture behavior of woven glass fiber reinforced polymer (GFRP) composite laminates at cryogenic temperatures. The eight-point bending plate (8PBP) tests were conducted at room temperature, liquid nitrogen temperature (77 K) and liquid helium temperature (4 K) using a new test fixture. A three-dimensional finite element analysis was also performed to calculate the energy release rate distribution along the delamination front, and the delamination fracture toughnesses were evaluated for various mixed-mode I/III ratios. Furthermore, the microscopic examinations of the fracture surfaces were carried out with scanning electron microscopy (SEM), and the mixed-mode I/III delamination fracture mechanisms in the woven GFRP laminates at cryogenic temperatures were assessed. The fracture properties were then correlated with the observed characteristics.

Damage Development in Hybrid Composite Laminates under Three-Point Bending at Cryogenic Temperatures

This paper studies the damage behavior and interlaminar shear properties of hybrid composite laminates subjected to bending at cryogenic temperatures. Cryogenic short beam shear tests were performed on hybrid laminates combining woven glass fiber reinforced polymer (GFRP) composites with polyimide films, and microscopic observations of the specimens were made after the tests. A progressive damage analysis was also conducted to simulate the initiation and growth of damage in the specimens and to determine the interlaminar shear strength based on the maximum shear stress in the failure region. The predicted load-deflection curve and damage pattern show good agreement with the test results, and the numerically determined interlaminar shear strength is higher than the apparent interlaminar shear strength.