In this study,we prepare the specimens of three-dimensional random fibrous(3D RF)material along its through-the-thickness(TTT)and in-plane(IP)directions.The experimental tests of tensile and compressive properties as ...In this study,we prepare the specimens of three-dimensional random fibrous(3D RF)material along its through-the-thickness(TTT)and in-plane(IP)directions.The experimental tests of tensile and compressive properties as well as fracture toughness of 3D RF material are performed at elevated temperatures.Then,the porosity(83%,87%and 89%)and temperature dependence of the tensile and compressive strength,elastic modulus,fracture toughness and fracture surface energy of the 3D RF materials for both the TTT and IP directions are analyzed.From the results of the tensile strength and elastic modulus versus material porosities at various temperatures,we find that tensile strength and elastic modulus for the TTT direction are more sensitive to the porosity,but not for the IP direction.Fracture toughness increases firstly and then decreases at a certain critical temperature.Such critical temperature is found to be the lowest for the porosity of 83%.On the other hand,at below 1073 K,the temperature-dependent fracture surface energies with three porosities for the TTT direction show similar variation trends.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.11902046,11632014,11372238 and 11872049)the Chang Jiang Scholar Program and the 111 Project(Grant No.B18040)This work was also supported by the Fundam ental Research Funds for the Central Universities,CHD(Grant No.300102259302).
文摘In this study,we prepare the specimens of three-dimensional random fibrous(3D RF)material along its through-the-thickness(TTT)and in-plane(IP)directions.The experimental tests of tensile and compressive properties as well as fracture toughness of 3D RF material are performed at elevated temperatures.Then,the porosity(83%,87%and 89%)and temperature dependence of the tensile and compressive strength,elastic modulus,fracture toughness and fracture surface energy of the 3D RF materials for both the TTT and IP directions are analyzed.From the results of the tensile strength and elastic modulus versus material porosities at various temperatures,we find that tensile strength and elastic modulus for the TTT direction are more sensitive to the porosity,but not for the IP direction.Fracture toughness increases firstly and then decreases at a certain critical temperature.Such critical temperature is found to be the lowest for the porosity of 83%.On the other hand,at below 1073 K,the temperature-dependent fracture surface energies with three porosities for the TTT direction show similar variation trends.
