One possible way to prevent steel angles from vibrating under dynamic loads is by using damping techniques. Damping involves adding materials or structures that absorb or dissipate the energy generated by the vibrating steel angles. This can be achieved by attaching damping pads or strips made of viscoelastic materials to the steel angles, which help absorb and dissipate the vibration energy. Another approach is to incorporate dampers such as tuned mass dampers or friction dampers, which are designed to reduce vibrations by adding additional mass or introducing friction forces to counteract the dynamic loads. Proper design and reinforcement of the steel angles can also help to increase their stiffness and reduce the likelihood of vibration.