一种可用作随堂教具的新型光弹设备1)
A NEW PHOTOELASTIC EQUIPMENT FOR CLASSROOM TEACHING1)
-
摘要: 光弹性实验是一种全场和实时性的光学实验,它能将一些抽象的力学现象以图像的形式生动地展示给学生,大大提高教学效率和教学的趣味性。但现实情况是基础力学理论课时普遍被压缩,实验课时又很紧张,光弹性实验在教学上的优势不能充分发挥。本文介绍了一种可应用于随堂教学的新型光弹设备及其工作原理,它仅仅由集成了圆偏振片的LED光源、加载架和像素偏振相机组成,结构简单、可折叠,连同手提箱约重5 kg。该设备可由理论课教师轻松携带至教室,在十分钟内完成一些光弹教学实验并将实验结果投影在教室的大屏幕上,借助于事先准备好的教案,将实验结果正确地解读给学生。通过上述教改,我们在不增加课时的前提下充分发挥了光弹性实验在教学上的优势。Abstract: Photoelastic experiment is a full field and real-time optical experiment. It can vividly show some abstract mechanical phenomena to students in the form of images, which greatly improves the teaching efficiency and students interest. However, the reality is that the teaching time for basic mechanics theory is compressed, and the time for experimental class is very limited. The advantages of photoelastic experiment in teaching cannot be brought into full play. This paper introduces a new type of photoelastic equipment which can be used in classroom teaching to demonstrate its working principle. It is composed of only LED light source integrated with circular polarizer, loading frame and pixel polarizing camera. It has simple structure and can be folded. It weighs about 5kg together with suitcase. The equipment can be easily carried to the classroom to accomplish photoelastic teaching experiments in ten minutes. The experimental results can be displayed on the large screen of the classroom, and the underlying theories can be explained to students with a well prepared teaching plan. Through the above teaching reform, we give full play to the advantages of photoelastic experiment in teaching without increasing class hours.