Abstract: An inverse analysis combining standard experiments and the direct search algorithm is developed in this study to determine cohesive parameters of flexible adhesive joints. The experimental part includes the uniaxial tensile tests and the double cantilever sandwich beam tests, which are used to obtain fracture parameters. The concept of effective crack length is used to eliminate the effects of plastic deformation on the fracture energy. The inverse analysis, taking the experimental values as initial input, is based on the Hooke-Jeeves algorithm. The entire analysis is automatically performed by running a program, which incorporates the Hooke-Jeeves algorithm, the resultant database, calling the Finite Element Method (FEM) software and the construction of objective functions. The credibility and accuracy of the proposed inverse analysis is confirmed by propellant/insulation tests. Results indicate that this method is more computationally efficient than other inverse analysis methods using global optimization algorithms.