The hidden mechanics behind why modern railroad tracks lack expansion joints
While most materials expand or contract with temperature changes, continuous welded rail remains stable. This video explores the engineering principle of restrained thermal expansion and how it manages the stress of temperature fluctuations.
Most materials exhibit a nearly linear relationship between temperature changes and changes in length. In traditional rail systems, this expansion often requires gaps or joints to prevent damage. However, continuous welded rail utilizes a different approach: restrained thermal expansion. By leveraging the relationship between stress and strain, engineers can overcome the physical tendency of the metal to expand, effectively using internal stress to counteract the thermal effects that would otherwise require physical gaps.
Source: Why Railroads Don't Need Expansion Joints
