Fun With Java Seminar

Homework 7: Visualization

Background and Motivation

The visualization of the states of stress in a mechanical mechanism, building, or any specific load carrying object is of prime importance in stress analysis. The equations have been developed many decades ago and a visual means of representing the equations called Mohr's circle has also been available for many decades. The visualization technique is important for several different reasons:

• Some students are visually oriented in their learning style.
• The visual picture of the stress relationships gives interrelationships quickly.
• The visual picture helps in establishing whether or not the answer is reasonable.
• The dynamic relationship of the rotating element and the rotating diameter of the circle can only be shown using computer visualization techniques.
• The color relationships between the elements sides and the radii of the circle while rotating the element will be very helpful in establishing directions of the stresses.

For long the instructors have felt the need to have some visualization tool available for the students . There are a few specialized packages that do the job, but what is really required for a first course on mechanics of materials is a simple and to-the-point software the can be put on the web.

We decided to do something about it and the what better language than Java to do the job!

What to Read

For those of you who are have not taken any courses on the mechanics of materials, we have a step-by-step procedure for the three problems below at http://www.public.iastate.edu/~em324/610/hw5/part_A.html (for the first problem) and http://www.public.iastate.edu/~em324/610/hw5/part_B_and_C.html (for second and third problems).

Directions

This homework, like the others in this seminar, will be open-ended and somewhat ill-defined. we'll try to give you some idea of the difficulty/effort involved in each part. Do what you have time for.

Bring a printout of your code to class, and be prepared to discuss it with other people in the class.

Problems

1. Draw the Mohr's circle for a given state of stress. Find out the principle stresses and plot on a triangular wedge inclined at the angle theta_P (the standard method) as well as show on the circle. Also show the state of stress on a square element.
2. For any arbitray plane P inclined at an angle theta (with respect to the reference X-axis), draw a new square element inclined at an angle theta (with respect to the reference X-axis) and show the stresses acting on the faces. Also plot these new stresses on the Mohr's cirlce
3. Make an animated version of the whole process and let the user scan through all the theta's. Users should have the option of coninuous scan and a step-by-step scan. You need to rotate the square element (and keep on changing the value of stresses both on the square and on the Mohr's cirlce).