Interface driving force calculation with boundary elements

The driving force exerted on an interface during a phase transformation can be calculated with the jump in displacement gradient across the interface. We demonstrate the use of boundary elements for this calculation by using anisotropic, bimaterial Green's functions in the kernels of the boundary integrals. The special Green's functions contain the jump in displacement gradient analytically offering a substantial advantage over other numerical techniques in calculating the driving force. We provide details of the Green's function and illustrate the application to twin boundaries in the martensitic phase transformation of copper-aluminum-nickel.