Particles penetrate inside a model when simulate program at high pressure.

My models can't endure with high pressure those particles will penetrate inside the models (particle go through the model when simulate at high pressure i can understand because it makes sense but some times low pressure also). In actually it shouldn't penetrate. I would like to ask you how to make model strong? I think it should has some parameters in LIGGGHTS that can make a wall strong enough for endure with high pressure simulation.

Thank you,
terces907