This work aims to investigate local stress distribution, damage evolution and failure of notched composite laminates under in-plane loads. An analytic method containing uniformed boundary equations using a complex var...This work aims to investigate local stress distribution, damage evolution and failure of notched composite laminates under in-plane loads. An analytic method containing uniformed boundary equations using a complex variable approach is developed to present layer-by-layer stresses around the notch. The uniformed boundary equations established in series together with conformal mapping functions are capable of dealing with irregular boundary issues around the notch and at infinity. Stress results are employed to evaluate the damage initiation and propagation of notched composites by progressive damage analysis（PDA）. A user-defined subroutine is developed in the finite element（FE） model based on coupling theories for mixed failure criteria and damage mechanics to efficiently investigate damage evolution as well as failure modes. Carbon/epoxy laminates with a stacking sequence of [45°/0°/ 60°/90°]sare used to investigate surface strains, in-plane load capacity and microstructure of failure zones to provide analytic and FE methods with strong validation. Good agreement is observed between the analytic method, the FE model and experiments in terms of the stress（strain） distributions, damage evaluation and ultimate strength, and the layerby-layer stress components vary according to a combination effect of fiber orientation and loading type, causing diverse failure modes in individuals.展开更多
The amphetamine derivative 3,4-methylenedioxymethamphetamine (MDMA), also called ecstasy, is a neurotoxin widely consumed among young people that has increased in recent years because it is a recreational drug, of whi...The amphetamine derivative 3,4-methylenedioxymethamphetamine (MDMA), also called ecstasy, is a neurotoxin widely consumed among young people that has increased in recent years because it is a recreational drug, of which immediate effects are known such as a greater sensation of well-being, extroversion, increased sensory perception. However, its long-term effects have been described very little in the medical literature, including damage to the heart, central nervous system, kidney, etc. One of its little-known effects is hepatotoxicity, of which few cases are known associated with fulminant hepatitis, which is a rapidly deteriorating condition that is generally associated with a syndrome of multiple organ dysfunction and death. Therefore, it is very important to know this type of damage in the short and long term. The following case is of a 39-year-old man who came to our service due to jaundice syndrome and the only history of MDMA consumption, who as the days went by met the criteria for fulminant liver failure, with damage to multiple organs (organ dysfunction syndrome).展开更多
基金sponsored by the National Natural Science Foundation of China, with three different programs (No. 51275410, No. 51305349 and No. 51305352) that supports the present work financially
文摘This work aims to investigate local stress distribution, damage evolution and failure of notched composite laminates under in-plane loads. An analytic method containing uniformed boundary equations using a complex variable approach is developed to present layer-by-layer stresses around the notch. The uniformed boundary equations established in series together with conformal mapping functions are capable of dealing with irregular boundary issues around the notch and at infinity. Stress results are employed to evaluate the damage initiation and propagation of notched composites by progressive damage analysis（PDA）. A user-defined subroutine is developed in the finite element（FE） model based on coupling theories for mixed failure criteria and damage mechanics to efficiently investigate damage evolution as well as failure modes. Carbon/epoxy laminates with a stacking sequence of [45°/0°/ 60°/90°]sare used to investigate surface strains, in-plane load capacity and microstructure of failure zones to provide analytic and FE methods with strong validation. Good agreement is observed between the analytic method, the FE model and experiments in terms of the stress（strain） distributions, damage evaluation and ultimate strength, and the layerby-layer stress components vary according to a combination effect of fiber orientation and loading type, causing diverse failure modes in individuals.
文摘The amphetamine derivative 3,4-methylenedioxymethamphetamine (MDMA), also called ecstasy, is a neurotoxin widely consumed among young people that has increased in recent years because it is a recreational drug, of which immediate effects are known such as a greater sensation of well-being, extroversion, increased sensory perception. However, its long-term effects have been described very little in the medical literature, including damage to the heart, central nervous system, kidney, etc. One of its little-known effects is hepatotoxicity, of which few cases are known associated with fulminant hepatitis, which is a rapidly deteriorating condition that is generally associated with a syndrome of multiple organ dysfunction and death. Therefore, it is very important to know this type of damage in the short and long term. The following case is of a 39-year-old man who came to our service due to jaundice syndrome and the only history of MDMA consumption, who as the days went by met the criteria for fulminant liver failure, with damage to multiple organs (organ dysfunction syndrome).
