复合材料液体模塑成型工艺（Liquid Composite Molding，LCM）的低成本制造优势使其得到越来越多的关注和应用，但其加工过程中易产生空隙、干斑等缺陷。树脂传递模塑（Resin Transfer Moulding，RTM）、真空辅助树脂传递模塑（Vacuum—...复合材料液体模塑成型工艺（Liquid Composite Molding，LCM）的低成本制造优势使其得到越来越多的关注和应用，但其加工过程中易产生空隙、干斑等缺陷。树脂传递模塑（Resin Transfer Moulding，RTM）、真空辅助树脂传递模塑（Vacuum—Assisted Resin Transfer Molding，VARTM）等复合材料液体模塑成型工艺（Liquid Composite Molding，LCM）由于具有设计灵活性、可成型大型复合构件、低成本制造等优势受到越来越多的研究和应用。展开更多
The effect of strain rate on fracture behavior of poly(methyl methacrylate) was investigated.The uniaxial tensile rupture tests for the poly(methyl methacrylate) samples were carried out at different strain rates at a...The effect of strain rate on fracture behavior of poly(methyl methacrylate) was investigated.The uniaxial tensile rupture tests for the poly(methyl methacrylate) samples were carried out at different strain rates at ambient temperature.It is found that the elastic modulus of the material increases with increasing strain rate,while the elongation is reversal with strain rate.Simultaneously,there exists a critical strain rate within which the stress-strain curves overlap one another,and beyond which the curves depart from each other.The amount of energy added to the system due to work done by the imposed load was calculated,and the strain energy stored in the material at each strain rate was calculated by the current stress integral with respect to strain.The complementary strain energy,which is the difference between the work and the strain energy,was obtained and was considered to supply the surface energy to create a new crack surface in the polymeric material.It is found that the work done by the imposed load,which is needed for the fracture of poly(methyl methacrylate) sample,decreases with increasing strain rate,and the strain energy decreases with strain rate as well,which demonstrates that the polymeric material at high strain rate is easier to fracture than that at low strain rate.As the strain rate increases,the fracture mode changes from ductile,semi-ductile to brittle mode.The complementary strain energy almost sustains a constant at any strain rate.The density of surface energy,which characterizes the energy per unit area needed for creating crack surface,is a strain rate-independent material constant.展开更多
文摘复合材料液体模塑成型工艺（Liquid Composite Molding，LCM）的低成本制造优势使其得到越来越多的关注和应用，但其加工过程中易产生空隙、干斑等缺陷。树脂传递模塑（Resin Transfer Moulding，RTM）、真空辅助树脂传递模塑（Vacuum—Assisted Resin Transfer Molding，VARTM）等复合材料液体模塑成型工艺（Liquid Composite Molding，LCM）由于具有设计灵活性、可成型大型复合构件、低成本制造等优势受到越来越多的研究和应用。
基金Projects(10772156,10672136) supported by the National Natural Science Foundation of China
文摘The effect of strain rate on fracture behavior of poly(methyl methacrylate) was investigated.The uniaxial tensile rupture tests for the poly(methyl methacrylate) samples were carried out at different strain rates at ambient temperature.It is found that the elastic modulus of the material increases with increasing strain rate,while the elongation is reversal with strain rate.Simultaneously,there exists a critical strain rate within which the stress-strain curves overlap one another,and beyond which the curves depart from each other.The amount of energy added to the system due to work done by the imposed load was calculated,and the strain energy stored in the material at each strain rate was calculated by the current stress integral with respect to strain.The complementary strain energy,which is the difference between the work and the strain energy,was obtained and was considered to supply the surface energy to create a new crack surface in the polymeric material.It is found that the work done by the imposed load,which is needed for the fracture of poly(methyl methacrylate) sample,decreases with increasing strain rate,and the strain energy decreases with strain rate as well,which demonstrates that the polymeric material at high strain rate is easier to fracture than that at low strain rate.As the strain rate increases,the fracture mode changes from ductile,semi-ductile to brittle mode.The complementary strain energy almost sustains a constant at any strain rate.The density of surface energy,which characterizes the energy per unit area needed for creating crack surface,is a strain rate-independent material constant.
