Aluminium alloys can exhibit changes in strength when subjected to varying loads compared to static loads. The discussion highlights the importance of understanding cyclic loading, particularly in relation to the S-N curve and the Bauschinger Effect, which are critical in assessing material fatigue. The strongest aluminium alloy mentioned is AlCu4Mg2, although 7001-T6 is noted for its high tensile strength of approximately 97 ksi, with an endurance limit of 21.8 ksi for cyclic loading. When subjected to cyclic loads, especially beyond the yield point, the material may experience strain hardening, increasing its strength but also making it more brittle, which negatively affects its fatigue life. The specific strength characteristics can vary significantly based on the type of alloy and the nature of the applied loads.