Based on the first order shear deformation theory(FSDT), the nonlinear dynamic equations involving transverse shear deformation and initial geometric imperfections were obtained by Hamilton's philosophy. Geometric...Based on the first order shear deformation theory(FSDT), the nonlinear dynamic equations involving transverse shear deformation and initial geometric imperfections were obtained by Hamilton's philosophy. Geometric deformation of the composite cylindrical shell was treated as the initial geometric imperfection in the dynamic equations, which were solved by the semi-analytical method in this paper. Stiffness reduction was employed for the damaged sub-layer, and the equivalent stiffness matrix was obtained for the delaminated area. By circumferential Fourier series expansions for shell displacements and loads and by using Galerkin technique, the nonlinear partial differential equations were transformed to ordinary differential equations which were finally solved by the finite difference method. The buckling was judged from shell responses by B-R criteria, and critical loads were then determined. The effect of the initial geometric deformation on the dynamic response and buckling of composite cylindrical shell was also discussed, as well as the effects of concomitant delamination and sub-layer matrix damages.展开更多
Penetrating cerebral injuries caused by foreign bodies are rare in civilian neurosurgical trauma, al- though there are various reports of blast or gunshot injuries in warfare due to multiple foreign bodies like pellet...Penetrating cerebral injuries caused by foreign bodies are rare in civilian neurosurgical trauma, al- though there are various reports of blast or gunshot injuries in warfare due to multiple foreign bodies like pellets and nails. In our case, a 30-year-old man presented to neurosurgery clinic with signs and symptoms of right-sided weakness after suicide bomb attack. The skull X-ray showed a single intracranial nail. Small craniotomy was done and the nail was removed with caution to avoid injury to surrounding normal brain tissue. At 6 months＇ follow-up his right- sided power improved to against gravity.展开更多
基金The National Natural Science Foundation of China (No.10202013)
文摘Based on the first order shear deformation theory(FSDT), the nonlinear dynamic equations involving transverse shear deformation and initial geometric imperfections were obtained by Hamilton's philosophy. Geometric deformation of the composite cylindrical shell was treated as the initial geometric imperfection in the dynamic equations, which were solved by the semi-analytical method in this paper. Stiffness reduction was employed for the damaged sub-layer, and the equivalent stiffness matrix was obtained for the delaminated area. By circumferential Fourier series expansions for shell displacements and loads and by using Galerkin technique, the nonlinear partial differential equations were transformed to ordinary differential equations which were finally solved by the finite difference method. The buckling was judged from shell responses by B-R criteria, and critical loads were then determined. The effect of the initial geometric deformation on the dynamic response and buckling of composite cylindrical shell was also discussed, as well as the effects of concomitant delamination and sub-layer matrix damages.
文摘Penetrating cerebral injuries caused by foreign bodies are rare in civilian neurosurgical trauma, al- though there are various reports of blast or gunshot injuries in warfare due to multiple foreign bodies like pellets and nails. In our case, a 30-year-old man presented to neurosurgery clinic with signs and symptoms of right-sided weakness after suicide bomb attack. The skull X-ray showed a single intracranial nail. Small craniotomy was done and the nail was removed with caution to avoid injury to surrounding normal brain tissue. At 6 months＇ follow-up his right- sided power improved to against gravity.
