What best describes a Compatible mesh?

A compatible mesh is best described as one where elements on touching bodies have overlapping or matching nodes. This type of mesh ensures that the interaction between adjacent elements is physically continuous, allowing for accurate simulations, especially in cases where different parts of an assembly are in contact with each other. By having nodes that align perfectly at the interfaces, it minimizes artifacts in the results that can arise from discontinuities, leading to improved accuracy in stress, strain, and displacement predictions during the simulation.

The concept of having overlapping nodes is particularly important in finite element analysis, where the shared behavior of connected parts must be accurately represented to capture the overall response of the system being modeled. Thus, option B clearly describes the essence of a compatible mesh, focusing on the continuity and interaction between elements.