Double labeled isocyanate resins for the solid-state NMR detection of urethane linkages to wood

In this paper we present a technique based on the finite element method, formulated in displacement, that enables stress conditions to be imposed. We use the method to impose the equilibrium condition at the interface of two bonded joints. We also show how the method reduces the times for repetitive calculations of structures such as bonded assemblies. We show that a calculation by standard FEM can have errors in the case of heterogeneous structures. We give the example of the calculation of a single lap joint and compare this with the mixed finite element method.