The Experts below are selected from a list of 82470 Experts worldwide ranked by ideXlab platform
Ping Liu - One of the best experts on this subject based on the ideXlab platform.
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mode i delamination mechanism analysis on cfrp interference fit during the Installation Process
Materials & Design, 2017Co-Authors: P Zou, Kaifu Zhang, Ping Liu, Heng ZhongAbstract:Abstract The wide application of composite materials in aerospace raises a new challenge for the joining technology. Though interference-fit can enhance joint strength, potential delamination damage also emerges for oversized percentage. A delamination analytical model during the interference-fit pin Installation Process is established in this paper. It consists of the critical delamination force (CDF) induced by mode I delamination and the pin-hole friction. The establishment of CDF model is based on fracture mechanics, classical bending plate theory and the mechanics of composites, and the friction model is built with classical anisotropic plate theory and friction law. Cohesive element (CE) based delamination simulation with bilinear softening constitutive law is made, and corresponding pin Installation experiments are also conducted. The effect of interference-fit percentages and residual layers on CDF was analyzed and the critical interference percentage below which delamination-free hole can be obtained was also proposed. Finite-element delamination results and experimental delamination specimens were analyzed and the rationality of the model was testified.
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micromechanical analysis for microscopic damage initiation in fiber epoxy composite during interference fit pin Installation
Materials & Design, 2016Co-Authors: Danlong Song, Kaifu Zhang, Hui Cheng, Ping LiuAbstract:Abstract The interference-fit joint of composite structures is widely used in thin-walled sheets assembly of aviation field. Understanding the microscopic damage mechanism during interference-fit pin Installation Process has a great importance for optimal design of interference-fit joints. Therefore, a novel multi-scale modeling approach is proposed to simulate and analyze the squeezed damage of microscopic representative volume elements (RVEs) during interference-fit pin Installation Process by 2D finite element models on ABAQUS platform with user-defined material subroutine (UMAT). The plane stress and strain formulations are employed for in-plane and through-thickness models respectively. Once the maximum principal stress reaches the corresponding strength, linear elastic carbon fibers fail. The epoxy resin matrix is considered to be elastoplastic. When the ultimate strength is reached, the stiffness properties begin to degrade. A cohesive zone model is used to simulate interface debonding between the fiber and matrix. It's observed that the vicinity of 30° angle between normal pressure and fiber direction at the entrance of hole is the weakest portion. In addition, the plastic deformation of epoxy matrix occurs first, followed by interfacial debonding. Then compressive damage of epoxy matrix is observed with the increase of interference value, which is similar to the micrograph by experiment.
Dave Kim - One of the best experts on this subject based on the ideXlab platform.
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an experimental and numerical study on the interference fit pin Installation Process for cross ply glass fiber reinforced plastics gfrp
Composites Part B-engineering, 2013Co-Authors: Sangyoung Kim, Chunsik Shim, Dave KimAbstract:Abstract Interference-fit pin connections provide beneficial effects such as fatigue enhancement to the fiber reinforced composites. An interference-fit pin Installation Process simulation using three-dimensional (3-D) finite element analysis (FEA) was conducted considering the friction coefficient (0.1) and interference-fit percentages (0.4% and 1.0%). During the simulation, the stress and strain distributions of GFRP when installing interference-fit pin were investigated. The radial and the tangential strains in the vicinity of the hole acquired from the FEA were compared with strain gauge experimental measurements, showing fairly good agreement. With increasing interference fit percent, the strain magnitudes increased after pin Installation. For 1% interference-fit, micro-scale fiber damage occurred in local regions around hole during the pin Installation experiments, while minimal damage was observed for 0.4% interference-fit.
Kaifu Zhang - One of the best experts on this subject based on the ideXlab platform.
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mode i delamination mechanism analysis on cfrp interference fit during the Installation Process
Materials & Design, 2017Co-Authors: P Zou, Kaifu Zhang, Ping Liu, Heng ZhongAbstract:Abstract The wide application of composite materials in aerospace raises a new challenge for the joining technology. Though interference-fit can enhance joint strength, potential delamination damage also emerges for oversized percentage. A delamination analytical model during the interference-fit pin Installation Process is established in this paper. It consists of the critical delamination force (CDF) induced by mode I delamination and the pin-hole friction. The establishment of CDF model is based on fracture mechanics, classical bending plate theory and the mechanics of composites, and the friction model is built with classical anisotropic plate theory and friction law. Cohesive element (CE) based delamination simulation with bilinear softening constitutive law is made, and corresponding pin Installation experiments are also conducted. The effect of interference-fit percentages and residual layers on CDF was analyzed and the critical interference percentage below which delamination-free hole can be obtained was also proposed. Finite-element delamination results and experimental delamination specimens were analyzed and the rationality of the model was testified.
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micromechanical analysis for microscopic damage initiation in fiber epoxy composite during interference fit pin Installation
Materials & Design, 2016Co-Authors: Danlong Song, Kaifu Zhang, Hui Cheng, Ping LiuAbstract:Abstract The interference-fit joint of composite structures is widely used in thin-walled sheets assembly of aviation field. Understanding the microscopic damage mechanism during interference-fit pin Installation Process has a great importance for optimal design of interference-fit joints. Therefore, a novel multi-scale modeling approach is proposed to simulate and analyze the squeezed damage of microscopic representative volume elements (RVEs) during interference-fit pin Installation Process by 2D finite element models on ABAQUS platform with user-defined material subroutine (UMAT). The plane stress and strain formulations are employed for in-plane and through-thickness models respectively. Once the maximum principal stress reaches the corresponding strength, linear elastic carbon fibers fail. The epoxy resin matrix is considered to be elastoplastic. When the ultimate strength is reached, the stiffness properties begin to degrade. A cohesive zone model is used to simulate interface debonding between the fiber and matrix. It's observed that the vicinity of 30° angle between normal pressure and fiber direction at the entrance of hole is the weakest portion. In addition, the plastic deformation of epoxy matrix occurs first, followed by interfacial debonding. Then compressive damage of epoxy matrix is observed with the increase of interference value, which is similar to the micrograph by experiment.
Sigrid Ringdalen Vatne - One of the best experts on this subject based on the ideXlab platform.
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towards a risk based decision support for offshore wind turbine Installation and operation maintenance
Energy Procedia, 2016Co-Authors: Tomas Gintautas, John Dalsgaard Sorensen, Sigrid Ringdalen VatneAbstract:Abstract Costs of operation & maintenance, assembly, transport and Installation of offshore wind turbines contribute significantly to the total cost of offshore wind farm. These operations are mostly carried out by specific ships that have to be hired for the operational phase and for duration of Installation Process, respectively. Duration, and therefore ship hiring costs is, among others, driven by waiting time for weather windows for weather-sensitive operations. Today, state of the art decision making criteria for weather-sensitive operations are restrictions to the significant wave height and the average wind velocity at reference height. However, actual limitations are physical, related to response of equipment used e.g. crane wire tension, rotor assembly motions while lifting, etc. Transition from weather condition limits to limits on physical equipment response in decision making would improve weather window predictions, potentially reducing cost of offshore wind energy. This paper presents a novel approach to weather window estimation using ensemble weather forecasts and statistical analysis of simulated Installation equipment response.
Sangyoung Kim - One of the best experts on this subject based on the ideXlab platform.
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an experimental and numerical study on the interference fit pin Installation Process for cross ply glass fiber reinforced plastics gfrp
Composites Part B-engineering, 2013Co-Authors: Sangyoung Kim, Chunsik Shim, Dave KimAbstract:Abstract Interference-fit pin connections provide beneficial effects such as fatigue enhancement to the fiber reinforced composites. An interference-fit pin Installation Process simulation using three-dimensional (3-D) finite element analysis (FEA) was conducted considering the friction coefficient (0.1) and interference-fit percentages (0.4% and 1.0%). During the simulation, the stress and strain distributions of GFRP when installing interference-fit pin were investigated. The radial and the tangential strains in the vicinity of the hole acquired from the FEA were compared with strain gauge experimental measurements, showing fairly good agreement. With increasing interference fit percent, the strain magnitudes increased after pin Installation. For 1% interference-fit, micro-scale fiber damage occurred in local regions around hole during the pin Installation experiments, while minimal damage was observed for 0.4% interference-fit.
