A damage prediction method based on FE simulation was proposed to predict the occurrence of hot shortness crocks and surface cracks in liquid-solid extrusion process. This method integrated the critical temperature cr...A damage prediction method based on FE simulation was proposed to predict the occurrence of hot shortness crocks and surface cracks in liquid-solid extrusion process. This method integrated the critical temperature criterion and Cockcroft ＆ Latham ductile damage model, which were used to predict the initiation of hot shortness cracks and surface cracks of products, respectively. A coupling simulation of deformation with heat transfer as well as ductile damage was carried out to investigate the effect of extrusion temperature and extrusion speed on the damage behavior of Csf/AZ91D composites. It is concluded that the semisolid zone moves gradually toward deformation zone with the punch descending. The amplitude of the temperature rise at the exit of die from the initial billet temperature increases with the increase of extrusion speed during steady-state extrusion at a given punch displacement. In order to prevent the surface temperature of products beyond the incipient melting temperature of composites, the critical extrusion speed is decreased with the increase of extrusion temperature, otherwise the hot shortness cracks will occur. The maximum damage values increase with increasing extrusion speed or extrusion temperature. Theoretical results obtained by the Deform^TM-2D simulation agree well with the experiments.展开更多
Exploited the forecast system of mining damages, which uses the theory of clean-production in coal-areas as guide. Its aims is developing and using coal resource reasonably and reducing the damage to the environment.
Seismic damage indices of structure are widely used to quantificationally analyze structural damage levels under earthquake action. In this paper, a five-storey building model and a seventeen-storey building model are...Seismic damage indices of structure are widely used to quantificationally analyze structural damage levels under earthquake action. In this paper, a five-storey building model and a seventeen-storey building model are established. According to seven typical indices and different earthquake-inputs, a structural damage prediction is performed, with the results showing serious uncertainty of structural damage prediction due to different indices. Understanding of this phenomenon aids the comprehension and application of the results of earthquake damage prediction.展开更多
Purpose： Suicide becomes a serious problem in today＇s society and hanging is a common method of suicide. We want to find the factors which can predict the final functional outcomes of these cases. Methods： All pati...Purpose： Suicide becomes a serious problem in today＇s society and hanging is a common method of suicide. We want to find the factors which can predict the final functional outcomes of these cases. Methods： All patients who presented to Accident and Emergency Department （ED） of the National Cheng Kung University Hospital from 1st January 2005 to 31th December 2013 with a hanging injury were included in this study. All cases were divided into good outcome group and bad outcome group according to Glasgow Outcome Scale （GOS）. Data was analyzed by Mann-Whitney test and chi-square test. Results： Glasgow Coma Scale （GCS） 〈 3, pupil dilation and no pupillary light reflex both at the scene and ED were the factors to indicate poor functional outcome. Out-hospital cardiac arrest （OHCA）, acidosis （pH 〈 Z2） and the need for intubation once arriving at ED were also related to poor functional outcome. OHCA cases all had poor functional outcome, Conclusion： GCS, pupil size, pupiUary light reflex, OHCA and acidosis are useful as prognostic factors. GCS= 3 lead to a very poor outcome. However, the functional outcome seems good in patients with GCS〉3. There parameters can help to predict the outcome before treatment.展开更多
基金Project(50972121) supported by the National Natural Science Foundation of China
文摘A damage prediction method based on FE simulation was proposed to predict the occurrence of hot shortness crocks and surface cracks in liquid-solid extrusion process. This method integrated the critical temperature criterion and Cockcroft ＆ Latham ductile damage model, which were used to predict the initiation of hot shortness cracks and surface cracks of products, respectively. A coupling simulation of deformation with heat transfer as well as ductile damage was carried out to investigate the effect of extrusion temperature and extrusion speed on the damage behavior of Csf/AZ91D composites. It is concluded that the semisolid zone moves gradually toward deformation zone with the punch descending. The amplitude of the temperature rise at the exit of die from the initial billet temperature increases with the increase of extrusion speed during steady-state extrusion at a given punch displacement. In order to prevent the surface temperature of products beyond the incipient melting temperature of composites, the critical extrusion speed is decreased with the increase of extrusion temperature, otherwise the hot shortness cracks will occur. The maximum damage values increase with increasing extrusion speed or extrusion temperature. Theoretical results obtained by the Deform^TM-2D simulation agree well with the experiments.
文摘Exploited the forecast system of mining damages, which uses the theory of clean-production in coal-areas as guide. Its aims is developing and using coal resource reasonably and reducing the damage to the environment.
基金sponsored by the National Basic Research Programof China (2006BAC13B02)the Science and Technology Special Program for Seismology, China Earthquake Administration (200708003)
文摘Seismic damage indices of structure are widely used to quantificationally analyze structural damage levels under earthquake action. In this paper, a five-storey building model and a seventeen-storey building model are established. According to seven typical indices and different earthquake-inputs, a structural damage prediction is performed, with the results showing serious uncertainty of structural damage prediction due to different indices. Understanding of this phenomenon aids the comprehension and application of the results of earthquake damage prediction.
文摘Purpose： Suicide becomes a serious problem in today＇s society and hanging is a common method of suicide. We want to find the factors which can predict the final functional outcomes of these cases. Methods： All patients who presented to Accident and Emergency Department （ED） of the National Cheng Kung University Hospital from 1st January 2005 to 31th December 2013 with a hanging injury were included in this study. All cases were divided into good outcome group and bad outcome group according to Glasgow Outcome Scale （GOS）. Data was analyzed by Mann-Whitney test and chi-square test. Results： Glasgow Coma Scale （GCS） 〈 3, pupil dilation and no pupillary light reflex both at the scene and ED were the factors to indicate poor functional outcome. Out-hospital cardiac arrest （OHCA）, acidosis （pH 〈 Z2） and the need for intubation once arriving at ED were also related to poor functional outcome. OHCA cases all had poor functional outcome, Conclusion： GCS, pupil size, pupiUary light reflex, OHCA and acidosis are useful as prognostic factors. GCS= 3 lead to a very poor outcome. However, the functional outcome seems good in patients with GCS〉3. There parameters can help to predict the outcome before treatment.
