Simple daily variations in temperature are unlikely to create significant micro-fractures or fatigue in aluminum or steel motorcycle or car frames due to thermal expansion alone, without any additional external factors.
Metals such as aluminum and steel have relatively high thermal conductivity, which means they can effectively dissipate heat and handle temperature changes without significant internal stress buildup. Additionally, these materials have a certain degree of flexibility and can withstand small thermal expansion and contraction without experiencing permanent damage.
However, it's worth noting that extreme temperature fluctuations, especially when combined with other factors, can potentially contribute to fatigue and stress on the vehicle frame over an extended period. Factors such as repeated exposure to extreme temperatures, rapid temperature changes, and thermal cycling can gradually affect the structural integrity of the frame. This could be exacerbated by factors like vibration, mechanical stress, or corrosion.
Manufacturers typically design vehicle frames to withstand a range of operating conditions, including temperature variations, and conduct extensive testing to ensure their durability. So, while daily temperature variations alone are unlikely to cause significant damage, it is important to consider other factors such as overall vehicle usage, maintenance, and exposure to harsh conditions that could contribute to the potential for micro-fractures or fatigue in the long term.
Regular inspections and maintenance, following manufacturer guidelines, will help ensure the safety and structural integrity of the vehicle frame over its lifespan.