The Experts below are selected from a list of 1095 Experts worldwide ranked by ideXlab platform
Xiaoping Zhong - One of the best experts on this subject based on the ideXlab platform.
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the impact damage and residual load capacity of composite stepped bonding repairs and joints
Composites Part B-engineering, 2019Co-Authors: Bin Liu, Qing Han, Xiaoping ZhongAbstract:Abstract Step topology Adhesively Bonded Structure is preferable applied in composite repairs and joints of primary load-bearing Structure. The failure mechanism and responses under low velocity impact are still not expressly revealed. A series of experiments for impact are conducted. Responses of impact contact load, deflection, absorbed energy and speed were tested. A critical impact energy of adhesive damage and residual strength was found. Above the energy level, tension capability after impact would drop largely. The stepped adhesive damage occur in the second step to the fifth step. The bondline damage modes include adhesive cohesive failure, composite-adhesive interface failure, matrix crack, interlamina delamination. The failure adhesive, interlamina, and matrix are bear tension-shear combined stress in the bottom-half at thickness direction. To testify the failure mechanism and reveal more, a progressive damage model of FEM based on zero thickness cohesive zone method was built. The constitutive relation is considered linear strain softening. The simulation results show more accurate damage detail of adhesive and composite materials with time varying. Synthesizing experimentation and simulation, the failure mechanism of composite stepped Structure with impact load is distinctly known. The experimental results also help the parametric inversion of the simulated model. The cohesive zone element parameters of stiffness, strength and fracture toughness are validated and useful.
Bin Liu - One of the best experts on this subject based on the ideXlab platform.
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the impact damage and residual load capacity of composite stepped bonding repairs and joints
Composites Part B-engineering, 2019Co-Authors: Bin Liu, Qing Han, Xiaoping ZhongAbstract:Abstract Step topology Adhesively Bonded Structure is preferable applied in composite repairs and joints of primary load-bearing Structure. The failure mechanism and responses under low velocity impact are still not expressly revealed. A series of experiments for impact are conducted. Responses of impact contact load, deflection, absorbed energy and speed were tested. A critical impact energy of adhesive damage and residual strength was found. Above the energy level, tension capability after impact would drop largely. The stepped adhesive damage occur in the second step to the fifth step. The bondline damage modes include adhesive cohesive failure, composite-adhesive interface failure, matrix crack, interlamina delamination. The failure adhesive, interlamina, and matrix are bear tension-shear combined stress in the bottom-half at thickness direction. To testify the failure mechanism and reveal more, a progressive damage model of FEM based on zero thickness cohesive zone method was built. The constitutive relation is considered linear strain softening. The simulation results show more accurate damage detail of adhesive and composite materials with time varying. Synthesizing experimentation and simulation, the failure mechanism of composite stepped Structure with impact load is distinctly known. The experimental results also help the parametric inversion of the simulated model. The cohesive zone element parameters of stiffness, strength and fracture toughness are validated and useful.
Qing Han - One of the best experts on this subject based on the ideXlab platform.
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the impact damage and residual load capacity of composite stepped bonding repairs and joints
Composites Part B-engineering, 2019Co-Authors: Bin Liu, Qing Han, Xiaoping ZhongAbstract:Abstract Step topology Adhesively Bonded Structure is preferable applied in composite repairs and joints of primary load-bearing Structure. The failure mechanism and responses under low velocity impact are still not expressly revealed. A series of experiments for impact are conducted. Responses of impact contact load, deflection, absorbed energy and speed were tested. A critical impact energy of adhesive damage and residual strength was found. Above the energy level, tension capability after impact would drop largely. The stepped adhesive damage occur in the second step to the fifth step. The bondline damage modes include adhesive cohesive failure, composite-adhesive interface failure, matrix crack, interlamina delamination. The failure adhesive, interlamina, and matrix are bear tension-shear combined stress in the bottom-half at thickness direction. To testify the failure mechanism and reveal more, a progressive damage model of FEM based on zero thickness cohesive zone method was built. The constitutive relation is considered linear strain softening. The simulation results show more accurate damage detail of adhesive and composite materials with time varying. Synthesizing experimentation and simulation, the failure mechanism of composite stepped Structure with impact load is distinctly known. The experimental results also help the parametric inversion of the simulated model. The cohesive zone element parameters of stiffness, strength and fracture toughness are validated and useful.
Dai Gil Lee - One of the best experts on this subject based on the ideXlab platform.
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The design of an optical sensor arrangement for the detection of oil contamination in an Adhesively Bonded Structure of a liquefied natural gas (LNG) ship
Measurement Science and Technology, 2009Co-Authors: Bu Gi Kim, Dai Gil LeeAbstract:Liquefied natural gas (LNG) has been widely used as a substitute fuel for commercial purposes. It is transported mainly by LNG ships which have primary and secondary leakage barriers. The former is composed of welded thin stainless steel or invar plates, while the latter is composed of Adhesively Bonded glass composite or aluminum foil sheets. The role of the secondary barrier is to maintain fluid tightness when the primary barrier fails during the transport of LNG. The tightness of the secondary barrier is dependent on the wetting characteristics between the adhesive and adherend of the Bonded Structure during bonding operation, which depends much on the contamination on the adherend surface. Therefore, in this work, an optical measuring device of oil contamination on the aluminum surface for the secondary barrier was developed. A transparent oil was used as the contaminant and its effect on the bonding strength was investigated. From the experiments, it has been found that the developed measuring device for oil contamination can be used to detect oil contamination on a large bonding area of the secondary barrier in ship building yards. © 2009 IOP Publishing Ltd.
Bu Gi Kim - One of the best experts on this subject based on the ideXlab platform.
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The design of an optical sensor arrangement for the detection of oil contamination in an Adhesively Bonded Structure of a liquefied natural gas (LNG) ship
Measurement Science and Technology, 2009Co-Authors: Bu Gi Kim, Dai Gil LeeAbstract:Liquefied natural gas (LNG) has been widely used as a substitute fuel for commercial purposes. It is transported mainly by LNG ships which have primary and secondary leakage barriers. The former is composed of welded thin stainless steel or invar plates, while the latter is composed of Adhesively Bonded glass composite or aluminum foil sheets. The role of the secondary barrier is to maintain fluid tightness when the primary barrier fails during the transport of LNG. The tightness of the secondary barrier is dependent on the wetting characteristics between the adhesive and adherend of the Bonded Structure during bonding operation, which depends much on the contamination on the adherend surface. Therefore, in this work, an optical measuring device of oil contamination on the aluminum surface for the secondary barrier was developed. A transparent oil was used as the contaminant and its effect on the bonding strength was investigated. From the experiments, it has been found that the developed measuring device for oil contamination can be used to detect oil contamination on a large bonding area of the secondary barrier in ship building yards. © 2009 IOP Publishing Ltd.