2017年北航-清华-北大三校“歼十杯”博士生学术文化节即将于本周末在顺鑫绿色度假村举行。来自北京航空航天大学best365官方网站登录入口的胡万林同学和孙国强同学将带来关于各自研究课题的宣讲。
胡万林同学的报告题目是《基于分子动力学的单晶镍纳米压痕模拟》。
报告内容是:本文采用分子动力学(MD)方法,对单晶镍(Ni)纳米压痕过程进行数值模拟,研究其在纳米尺度上的力学行为。绘出单晶镍基体在球形压头作用下的载荷-位移曲线,分析载荷与位移的关系,发现在加载过程中会产生“位移突进”现象。将分子动力学模拟的结果与经典Hertz接触理论的解析解进行对比,符合良好。分别作出加载速率、压头半径、压入深度、温度等不同因素下的载荷-位移曲线,并作定性的分析,研究发现:加载速率越大,压头半径越小,温度越高越容易发生“位移突进”现象,即越易发生局部的屈服;球形压头半径越大,残余塑形变形越大,塑形屈服区越大;不同压入深度的模拟结果,相当于同一加载过程的前后不同阶段,且压入深度越大,材料的硬度测量值会稍微增大。由载荷-位移图像求得材料的硬度和弹性模量,与材料实验测得的硬度和弹性模量相近。
孙国强同学的报告题目是《The influence of HUD information visual coding on pilot's situational awareness》。
报告内容是:Many researches of the visual coding on the information display of HUD but few studies focusing on the specific design of HUD display symbols. Based on the above studies, some important display symbols of the HUD would be used for ergonomics evaluation and the level of SA was adopted as measurement index. Based on the typical HUD interfaces, the HUD simulation interface was designed by GL Studio and Visual Studio software and referring to the classic HUD display format of foreign civil aircrafts. The experiment factors were set as HUD interface format including small aircraft symbol, relative position of heading and rolling indicators, display format of airspeed and altitude indicators. The SAGAT, 3-D SART, task performance and physiological measurement were used to assess the operator’s SA under different interface conditions during a whole flight silumation. As well as the humannity of different HUD display symbols were analyzed.