In this paper. from asymptotic equations of thicking shell obtained on the basis of the equations of three dimensional elastic mechanics using geometric small parameter we find the solutions of the stresses and the de...In this paper. from asymptotic equations of thicking shell obtained on the basis of the equations of three dimensional elastic mechanics using geometric small parameter we find the solutions of the stresses and the deformations of thick ring shell submitted to the action of internal pressure q.展开更多
The stress and the elastic deflection of internal ring gear in high-speed spur planetary gear units are investigated. A rim thickness parameter is defined as the flexibility of internal ring gear. Six evenly spaced li...The stress and the elastic deflection of internal ring gear in high-speed spur planetary gear units are investigated. A rim thickness parameter is defined as the flexibility of internal ring gear. Six evenly spaced linear springs are used to describe the fitting status between internal ring gear and the gearcase. The finite element model of the whole internal ring gear is established by means of Pro/E and ANSYS. The loads on meshing teeth of internal ring gear are applied according to the contact ratio and the load-sharing coefficient. With the finite element analysis (FEA), the influences of flexibility and fitting status on the stress and elastic deflection of internal ring gear are predicted. The simulation reveals that the principal stress and deflection increase with the decrease of rim thickness of internal ring gear. Moreover, larger spring stiffness helps to reduce the stress and deflection of internal ring gear. Therefore, the flexibility of internal ring gear must be considered during the design of high-speed planetary gear transmissions.展开更多
INTRODUCTIONAlthough laparoscopic herniorrhaphy is the most common procedure performed by pediatric surgeons at present, herniorrhaphy with an asymptomatic patent processus vaginalis （PPV） remains controversial. The...INTRODUCTIONAlthough laparoscopic herniorrhaphy is the most common procedure performed by pediatric surgeons at present, herniorrhaphy with an asymptomatic patent processus vaginalis （PPV） remains controversial. The incidence of contralateral PPV on laparoscopy in previous studies was reported as 20%-50%, but it is believed to approach 100% in premature infants. It has been reported that 4%-34% patients have the risk of developing subsequent metachronous contralateral hernia after a repair of an ipsilateral hernia.Iu If this is true, then the identification and closure of a PPV at the time of ipsilateral hernia repair will obviate the need for a second operation in thousands of children every year. With recent advances in minimally invasive surgery, transinguinal diagnostic laparoscopy has emerged as a safe and effective method for evaluating a pediatric patient with PPV. Meanwhile, the laparoscopy has been widely used to manage the infantile hypertrophic pyloric stenosis （IHPS）, due to equally high success rate, minimal complications, and a shorter hospital stay.展开更多
文摘In this paper. from asymptotic equations of thicking shell obtained on the basis of the equations of three dimensional elastic mechanics using geometric small parameter we find the solutions of the stresses and the deformations of thick ring shell submitted to the action of internal pressure q.
基金Key Project of Ministry of Education of China (No.106050).
文摘The stress and the elastic deflection of internal ring gear in high-speed spur planetary gear units are investigated. A rim thickness parameter is defined as the flexibility of internal ring gear. Six evenly spaced linear springs are used to describe the fitting status between internal ring gear and the gearcase. The finite element model of the whole internal ring gear is established by means of Pro/E and ANSYS. The loads on meshing teeth of internal ring gear are applied according to the contact ratio and the load-sharing coefficient. With the finite element analysis (FEA), the influences of flexibility and fitting status on the stress and elastic deflection of internal ring gear are predicted. The simulation reveals that the principal stress and deflection increase with the decrease of rim thickness of internal ring gear. Moreover, larger spring stiffness helps to reduce the stress and deflection of internal ring gear. Therefore, the flexibility of internal ring gear must be considered during the design of high-speed planetary gear transmissions.
文摘INTRODUCTIONAlthough laparoscopic herniorrhaphy is the most common procedure performed by pediatric surgeons at present, herniorrhaphy with an asymptomatic patent processus vaginalis （PPV） remains controversial. The incidence of contralateral PPV on laparoscopy in previous studies was reported as 20%-50%, but it is believed to approach 100% in premature infants. It has been reported that 4%-34% patients have the risk of developing subsequent metachronous contralateral hernia after a repair of an ipsilateral hernia.Iu If this is true, then the identification and closure of a PPV at the time of ipsilateral hernia repair will obviate the need for a second operation in thousands of children every year. With recent advances in minimally invasive surgery, transinguinal diagnostic laparoscopy has emerged as a safe and effective method for evaluating a pediatric patient with PPV. Meanwhile, the laparoscopy has been widely used to manage the infantile hypertrophic pyloric stenosis （IHPS）, due to equally high success rate, minimal complications, and a shorter hospital stay.
