In this study,the deformation and stress distribution of printed circuit board(PCB)with different thickness and composite materials under a shock loading were analyzed by the finite element analysis.The standard 8-lay...In this study,the deformation and stress distribution of printed circuit board(PCB)with different thickness and composite materials under a shock loading were analyzed by the finite element analysis.The standard 8-layer PCB subjected to a shock loading 1500 g was evaluated first.Moreover,the finite element models of the PCB with different thickness by stacking various number of layers were discussed.In addition to changing thickness,the core material of PCB was replaced from woven E-glass/epoxy to woven carbon fiber/epoxy for structural enhancement.The non-linear material property of copper foil was considered in the analysis.The results indicated that a thicker PCB has lower stress in the copper foil in PCBs under the shock loading.The stress difference between the thicker PCB(2.6 mm)and thinner PCB(0.6 mm)is around 5%.Using woven carbon fiber/epoxy as core material could lower the stress of copper foil around 6.6%under the shock loading 1500 g for the PCB with 0.6 mm thickness.On the other hand,the stress level is under the failure strength of PCBs with carbon fiber/epoxy core layers and thickness 2.6 mm when the peak acceleration changes from 1500 g to 5000 g.This study could provide a reference for the design and proper applications of the PCB with different thickness and composite materials.展开更多
Shell structure is widely used in industrial applications, such as in machinery, aerospace, ship and building fields, as well as containers of pressurized chemicals or liquefied natural gas. Graphite/epoxy composites ...Shell structure is widely used in industrial applications, such as in machinery, aerospace, ship and building fields, as well as containers of pressurized chemicals or liquefied natural gas. Graphite/epoxy composites has advantages of light weight, high strength, corrosion resistance, low expansion, low shrin kage and are often used in the form of composite pressure vessel for various engineering applications. In this study, the stress distributions of composite pressure vessel were analyzed. The finite element code ANSYS was used in analysis, in which the eight-node element SHELL 281 was adopted. The internal pressure 20 MPa, as in container of compressed natural gas, was applied inside the symmetrical cross-ply graphite/epoxy composite pressure vessel. The finite element model was established with suitable mesh size and boundary conditions. The stress distributions are discussed for the composite pressure vessel, especially for the inner two layers at the junction of semis pherical part. The Tsai-Hill criterion was used to assess the failure of composite pressure vessel.展开更多
基金the support from Ministry of Science and Technology,Taiwan,R.O.C.,through grant MOST-105-2221-E-007-031-MY3.
文摘In this study,the deformation and stress distribution of printed circuit board(PCB)with different thickness and composite materials under a shock loading were analyzed by the finite element analysis.The standard 8-layer PCB subjected to a shock loading 1500 g was evaluated first.Moreover,the finite element models of the PCB with different thickness by stacking various number of layers were discussed.In addition to changing thickness,the core material of PCB was replaced from woven E-glass/epoxy to woven carbon fiber/epoxy for structural enhancement.The non-linear material property of copper foil was considered in the analysis.The results indicated that a thicker PCB has lower stress in the copper foil in PCBs under the shock loading.The stress difference between the thicker PCB(2.6 mm)and thinner PCB(0.6 mm)is around 5%.Using woven carbon fiber/epoxy as core material could lower the stress of copper foil around 6.6%under the shock loading 1500 g for the PCB with 0.6 mm thickness.On the other hand,the stress level is under the failure strength of PCBs with carbon fiber/epoxy core layers and thickness 2.6 mm when the peak acceleration changes from 1500 g to 5000 g.This study could provide a reference for the design and proper applications of the PCB with different thickness and composite materials.
文摘Shell structure is widely used in industrial applications, such as in machinery, aerospace, ship and building fields, as well as containers of pressurized chemicals or liquefied natural gas. Graphite/epoxy composites has advantages of light weight, high strength, corrosion resistance, low expansion, low shrin kage and are often used in the form of composite pressure vessel for various engineering applications. In this study, the stress distributions of composite pressure vessel were analyzed. The finite element code ANSYS was used in analysis, in which the eight-node element SHELL 281 was adopted. The internal pressure 20 MPa, as in container of compressed natural gas, was applied inside the symmetrical cross-ply graphite/epoxy composite pressure vessel. The finite element model was established with suitable mesh size and boundary conditions. The stress distributions are discussed for the composite pressure vessel, especially for the inner two layers at the junction of semis pherical part. The Tsai-Hill criterion was used to assess the failure of composite pressure vessel.
