If there are drag and vertical loads acting on aircraft wheels, what is the design and ultimate standards/limits for civil aircraft? Are they usually 0.8g in drag and 1.5g in normal?
You might misunderstand my question. My questions were about landing gear structure strength to ground loads (drag/friction, normal/vertical). When we design landing gears, what are structure strength (design and ultimate loads) standards/limits?
If I understand your question, then the answer (in Canada and the US) is the limit and ultimate loads are determined through drop test. Using an effective weight the appropriate portion of the gear is dropped from a height based on wing loading. This substantiates the strength (except fatigue) of the structure. By instrumenting the drop test assembly with an accelerometer the resultant inertial loading can be determined. Loads for the rest of the aircraft structure are then based on this value. A relatively simple description of the process can be found in the older regulations (CAR 3 for instance). Typical values are in the 3-4 g range