How do an airliners fuselage and wings manage to survive repeated?
How do an airliners fuselage and wings manage to survive repeated fluctuations in temperature from, say, minus 60 degrees C at 30,000 feet to perhaps plus 30 at ground level, day after day, year after year? Designs and material selections are over-engineered in order to provide safety margins, and the assembly is rigorously tested to levels exceeding its guaranteed operational and performance envelop. Metallurgy and material sciences are also a mature discipline and failures as they apply to aviation are also well studied and understood. These mechanisms, plus rigorous routine inspections throughout an airliners service life will ensure problems and anomalies are detected and corrected well before failure occurs.