Peel test measurements and simulations of the interfacial mechanical parameters for the Al/Epoxy/Al2O3 system are performed in the present investigation. A series of Al film thicknesses between 20 and 250 microns and ...Peel test measurements and simulations of the interfacial mechanical parameters for the Al/Epoxy/Al2O3 system are performed in the present investigation. A series of Al film thicknesses between 20 and 250 microns and three peel angles of 90, 135 and 180 degrees are considered. Two types of epoxy adhesives are adopted to obtain both strong and weak interface adhesions. A finite element model with cohesive zone elements is used to identify the interfacial parameters and simulate the peel test process. By simulating and recording normal stress near the crack tip, the separation strength is obtained, Furthermore, the cohesive energy is identified by comparing the simulated steady-state peel force and the experimental result. It is found from the research that both the cohesive energy and the separation strength can be taken as the intrinsic interfacial parameters which are dependent on the thickness of the adhesive layer and independent of the film thickness and peel angle.展开更多
Regardless of all kinds of different formulae used for the traction-separation relationship in cohesive zone modeling,the peak tractionσ_m and the separation-to-failureδ_0(or equivalently the work-to-separationΓ) a...Regardless of all kinds of different formulae used for the traction-separation relationship in cohesive zone modeling,the peak tractionσ_m and the separation-to-failureδ_0(or equivalently the work-to-separationΓ) are the primary parameters which control the interfacial fracture behaviors. Experimentally,it is hard to determine those quantities,especially forδ_0,which occurs in a very localized region with possibly complicated geometries by material failure.Based on the Dugdale model,we show that the separation-to-failure of an interface could be amplified by a factor of L/r_p in a typical peeling test,where L is the beam length and r_p is the cohesive zone size.Such an amplifier makesδ_0 feasible to be probed quantitatively from a simple peeling test. The method proposed here may be of importance to understanding interfacial fractures of layered structures,or in some nanoscale mechanical phenomena such as delamination of thin films and coatings.展开更多
In the present study, peel tests and inverse analysis were performed to determine the interracial mechanical parameters for the metal film/ceramic system with an epoxy interface layer between film and ceramic. Al film...In the present study, peel tests and inverse analysis were performed to determine the interracial mechanical parameters for the metal film/ceramic system with an epoxy interface layer between film and ceramic. Al films with a series of thicknesses between 20 and 250 μm and three peel angles of 90°, 135° and 180° were considered. A finite element model with the cohesive zone elements was used to simulate the peeling process. The finite element results were taken as the training data of a neural network in the inverse analysis. The interracial cohesive energy and the separation strength can be determined based on the inverse analysis and peel experimental result展开更多
This paper tested the viscosity of prepreg in the automatic placement process, and conducted the probe and placement-90° peel tests through the test systems. The law of variation of prepreg viscosity during the l...This paper tested the viscosity of prepreg in the automatic placement process, and conducted the probe and placement-90° peel tests through the test systems. The law of variation of prepreg viscosity during the laying process was studied through these tests under different conditions by taking the peel force to intuitively and quantitatively characterise the viscosity of the prepreg.The results show that this viscosity is inversely proportional to the laying rate, proportional to the laying pressure, and quadratic to the laying temperature. Then, peel tests were simulated to validate both the correctness of the peel test and that of the probe test data fitting the two-line cohesion model. On this basis, a response surface test for laying and peeling was designed. Taking viscous peel force as the response target, the laying process parameters were optimised and the significance of their influence was further studied. The error between the test value and the predicted value of the maximum viscous peel force is 3.03%.展开更多
基金the Chinese Academy of Sciences (No.KJCX2-YW-M04) the National Science Foundationof China (Nos.10432050, 10672163 and 10721202).
文摘Peel test measurements and simulations of the interfacial mechanical parameters for the Al/Epoxy/Al2O3 system are performed in the present investigation. A series of Al film thicknesses between 20 and 250 microns and three peel angles of 90, 135 and 180 degrees are considered. Two types of epoxy adhesives are adopted to obtain both strong and weak interface adhesions. A finite element model with cohesive zone elements is used to identify the interfacial parameters and simulate the peel test process. By simulating and recording normal stress near the crack tip, the separation strength is obtained, Furthermore, the cohesive energy is identified by comparing the simulated steady-state peel force and the experimental result. It is found from the research that both the cohesive energy and the separation strength can be taken as the intrinsic interfacial parameters which are dependent on the thickness of the adhesive layer and independent of the film thickness and peel angle.
基金supported by the"Hundred Talent Program"from Chinese Academy of Sciences
文摘Regardless of all kinds of different formulae used for the traction-separation relationship in cohesive zone modeling,the peak tractionσ_m and the separation-to-failureδ_0(or equivalently the work-to-separationΓ) are the primary parameters which control the interfacial fracture behaviors. Experimentally,it is hard to determine those quantities,especially forδ_0,which occurs in a very localized region with possibly complicated geometries by material failure.Based on the Dugdale model,we show that the separation-to-failure of an interface could be amplified by a factor of L/r_p in a typical peeling test,where L is the beam length and r_p is the cohesive zone size.Such an amplifier makesδ_0 feasible to be probed quantitatively from a simple peeling test. The method proposed here may be of importance to understanding interfacial fractures of layered structures,or in some nanoscale mechanical phenomena such as delamination of thin films and coatings.
基金the Chinese Academy of Sciences(KJCX2-YW-M04)the National Natural Sciences Foundation of China(10432050,10428207,10672163,and 10721202)
文摘In the present study, peel tests and inverse analysis were performed to determine the interracial mechanical parameters for the metal film/ceramic system with an epoxy interface layer between film and ceramic. Al films with a series of thicknesses between 20 and 250 μm and three peel angles of 90°, 135° and 180° were considered. A finite element model with the cohesive zone elements was used to simulate the peeling process. The finite element results were taken as the training data of a neural network in the inverse analysis. The interracial cohesive energy and the separation strength can be determined based on the inverse analysis and peel experimental result
基金supported by the National Natural Science Foundation of China(No.51875159)the Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory,China(No.XHT 2020-002)+5 种基金Fok Ying Tung Education Foundation,China(No.171046)the Key Research and Development Program of Anhui Province,China(No.201904d07020013)the Fundamental Research Funds for the Central Universities,China(Nos.PA2020GDJQ0029 and PA2020GDSK0075)the National Key Research and Development Project,China(No.2019YFB1504800)the Beijing Natural Science Foundation,China(No.2192044)2020 and 2021 Open Project of State Key Laboratory of Organic-Inorganic Composites,China(Nos.Oic-202001008 and Oic-202101008)。
文摘This paper tested the viscosity of prepreg in the automatic placement process, and conducted the probe and placement-90° peel tests through the test systems. The law of variation of prepreg viscosity during the laying process was studied through these tests under different conditions by taking the peel force to intuitively and quantitatively characterise the viscosity of the prepreg.The results show that this viscosity is inversely proportional to the laying rate, proportional to the laying pressure, and quadratic to the laying temperature. Then, peel tests were simulated to validate both the correctness of the peel test and that of the probe test data fitting the two-line cohesion model. On this basis, a response surface test for laying and peeling was designed. Taking viscous peel force as the response target, the laying process parameters were optimised and the significance of their influence was further studied. The error between the test value and the predicted value of the maximum viscous peel force is 3.03%.