Development of a basic/simple simulator of mechanical behavior in 3 dimensions

Sammanfattning: This paper concerns the development of a simple simulator of mechanical systems, a basic program to model a body acted on by an outside force and extrapolate what is going to happen in the next moment. It should also be able to present the results graphically, in this case with 3D-graphics, as well as be reasonably faithful to what would actually happen. To achieve this, the programming language Java, with a heavy reliance on the code package Java 3D, was used. Java was chosen for the fact that it is well documented, and Java 3D because it provided useful tools that would be difficult to re-create from the ground up. In the model the simulator uses, solid bodies are treated as particles with a mass, position and velocity, while forces act as a point force on the body’s center of mass. The bodies are graphically represented by spheres. Each body also contains an algorithm to update its position from its current velocity and the forces acting upon it in the current time-step. This is accomplished through Euler’s Method, via Newton’s law connecting mass to acceleration. The simulator has purposefully been written in the simplest possible form, but has left room for adding more features in the future. Three example simulations have been included in the code in order to demonstrate the simulator. These are explained in this paper.