Patterns and Challenges of Undergraduate Project Work in Germany: The Aachen Experience

In this report, experiences are described which have been gained at the University of Technology, Aachen, in offering interdisciplinary, ‘real-life’ study projects (Studienarbeiten) to engineering undergraduates. The approach at this university is based on the regulation that every engineering student has to do two different study projects before starting on the Master research project (Diplomarbeit). The study projects described here are genuinely linked to the professional roles and tasks of engineers today. At the same time, they follow as much as possible the individual aims and areas of interests of the students involved.     

实现异步冲击的自动冲击装置:一种针对操作过程中模态测试的实用方案（英文）

目的:目前手动冲击锤设备缺乏对冲击时间的控制,容易引起冲击相位和周期荷载的周期性响应的相位同步问题。本文旨在通过使用异步自动冲击激励的自动冲击装置代替同步冲击模态分析中传统手动冲击锤的方法来解决上述问题。创新点:1.引入具有可调冲击参数的自动冲击装置;2.该装置可通过控制施加冲击的时间步来确保冲击和来自循环载荷组件的响应异步;3.当周期性响应的相位与装置所施加的冲击信号不一致时,加速响应中未知力源的影响会被降到最小。方法:1.分别使用数字方波信号的波峰和波谷来控制自动冲击装置的"开"和"关"状态;2.通过调控样本大小(1024个)、采样率(50 000个/秒)、占空比(0.5%)和冲击频率(97.78 Hz)(或周期)等参数得到不同的冲击图形。结论:1.使用可实现异步冲击的自动冲击装置可以估算第3阶自然模态;2.前3种自然模态可以被成功确定并与基准实验模态分析结果具有良好的相关性,表现为低于1.67%的自然频率差异,1.79%~12.54%的阻尼比差异以及介于0.893和0.925之间的模态置信度。3.针对谐波干扰对相位的影响,相比于使用手动冲击锤来增强频率响应函数估计和模态提取数据,使用可实现异步冲击的自动冲击装置是一种更可行的选择。     

Creativity at the Borders of Engineering: Three Personal Accounts

This paper deals with developing engineering creativity outside university education. Three personal accounts are reported here as the main content of this paper. They describe how young people wanted to fulfil their visions of creating unique artefacts in a very wide sense, and what engineering skills they had to develop on their own to achieve their goals. Professional engineers have assisted them in their striving without really being able to offer them, at that time, ready-made solutions. In this sense, the personal goals of these three people surpassed the present engineering experiences and they posed as yet insoluble problems to the profession. The personal accounts of these three people are presented here, to be followed by some brief conclusions for engineering education.