Beam Me Down : How Can Optimizations be Made?
You've seen how the section modulus and moment of inertia relate to the overall strength of the beam. Now the question remains: Can improvements be made?
The answer, in short, is yes. However, other factors must be taken into consideration when discussing improvements. For example, if you draw an I-beam using the Beam applet 5 units wide at the top and bottom, and 16 total units high, you will stay in the realm of 24 total units, and the section modulus and moment of inertia will be very high. However, such a beam may be very hard to manufacture. If you wanted to make the shape out of layers of foam, as the other beams were made, you would soon find it effort-prohibitive to assemble all the little strips perfectly.
Also, with such a design, it might be very hard to keep the load perfectly centered on the beam, causing the beam to fold top to bottom, as opposed to breaking in the middle. If you look closely at well-engineered beams, such as those used in bridges, you will notice that the overall width of the beam is almost always the same as its height. The center of 'professional' I-beams are typically about 2 - 3 times the thickness of the top and bottom flanges, to resist the folding mentioned before.
So, while improvement can be made to beam design, there comes a point beyond which you are not improving, but actually worsening the design!
Now that you have experience in experimenting to improve your designs, your on your way to being an engineer!