Abstract: This paper aims to investigate the equivalent model of the metal sandwich structure of platefin heat exchanger, which is based on the small bending deformation theory and orthotropic sandwich panel bending deformation theory. The equivalent mechanical parameters of the metal sandwich structure of platefin heat exchanger can be derived by making the finite element equivalent model. Using finite element pretreatment software Patran, the platefin exchanger sandwich structure is simplified and separated into a representative unit. The strain components and bending forces of the representative unit are simulated under duplicate constraints. According to the constitutive relations of the stress and strain of the sandwich panel, the stiffness matrix can be simulated, and then the macroscopic equivalent elastic constants are derived. Using this method, the platefin heat exchanger sandwich panel can be equaled into a continuous singleboard unit. Finally the mechanical properties of the equivalent model are applied to the mode analysis of the platefin heat exchanger. Comparing with the mode test results, the rationality and effectiveness of the equivalent analysis method are demonstrated.

Key words: plate-fin heat exchanger sandwich panels, finite element equivalent model, constitutive relations, equivalent elastic constant