The Architecture of Bridges: Tension and Compression
Understand how structures balance forces to stay upright.
Every bridge must manage two main forces: tension and compression. Compression is a squeezing force that pushes materials together, while tension is a pulling force that stretches them apart. A sturdy bridge is a masterpiece of balancing these two. For example, in a suspension bridge, the cables are in pure tension, carrying the load to towers that are in pure compression. By choosing materials that are strong in either tension (like steel) or compression (like concrete), engineers keep the bridge from collapsing.
Try this at home
Try to snap a dry spaghetti noodle by pulling the ends (tension) versus pushing them together (compression). You will notice it resists compression well but snaps instantly under tension, demonstrating why materials must be chosen based on force.