Can you overload a dually?

Laws of physics...flexing/bending/etc All THINGS FLEX...it depends on a few things in reference to that object in discussion. AKA "Tin Canning" to break something or not...that is determined by the design to not allow the object to go past it's plasticity range and go into the deformation range

A component to that is the rigidity of that object and the biggie: harmonics and the first/secondary/tertiary/etc frequency/amplitude

Amplitude is the force or in this case, part of that force is the weight being tossed around by the harmonics