Abstract
The stiffness of boundary conditions in mechanical structures is difficult to represent. An approach on high fidelity modeling of the clamped boundary condition is proposed in this paper. Firstly, the normal and tangential stiffness of the contact surface of the clamped boundary condition is parameterized by using thin-layer element with isotropic material. Secondly, the material parameter is identified by minimizing the discrepancy between the calculated results and the experimental data, and parameter identification can be treated as an optimization problem. Experimental investigation is undertaken to verify the proposed method by employing an aluminum honeycomb panel, the numerical model of which is constructed by using the equivalent theory. Thin-layer elements with different properties are used to simulate the mechanical properties in different area of the boundary conditions, and the experimental modal data is adopted to identify the material parameters. Results show that the weighted matrix is a crucial option in the parameter identification procedure, and the width to thickness ratio of the thin layer element has a great influence on the identification results. After parameter identification, the error of the first three order of the modal frequencies is less than 2.7 %, the thin-layer element can accurately reflect the mechanical performance of clamped boundary condition.
Highlights
Structural dynamic performance is strongly affected by boundary conditions, which should be considered appropriately in both theoretical and numerical analysis
The exist inappropriate methods for modeling of boundary stiffness, such as idealizing constraints into completely rigid and modelling ostensibly similar boundaries refer to the previous experiences, can be applied to characterize the boundary conditions in an oversimplified way, which will inevitably lead to errors in structural dynamics modeling
Mottershead et al [1] indicated that parameterization is critical in updating of boundary conditions, the boundary stiffness in a cantilever was modeled as the effective length of elements closest to the joint, but in some cases, the corrected matrices will lose connection to the physical significance while matching the experimental modal data
Summary
Structural dynamic performance is strongly affected by boundary conditions, which should be considered appropriately in both theoretical and numerical analysis. Simplified equivalent modeling is the alternative method to represent the contact mechanics relationship and the boundary stiffness. Pabst and Hagedorn [10] proposed an inverse method to identify the boundary stiffness and damping parameters of a visco-elastically clamped beam by using. Boundary stiffness are simplified as spring models in the above researches, modeling difficulties will arise when apply spring models to complex structures, and the deficiency is obvious for modeling large contact surface. Mottershead et al [1] indicated that parameterization is critical in updating of boundary conditions, the boundary stiffness in a cantilever was modeled as the effective length of elements closest to the joint, but in some cases, the corrected matrices will lose connection to the physical significance while matching the experimental modal data. Parameters such as the weight matrix used in the parameter identification, the width to thickness ration of the thin-layer element should be considered in the identification procedure, because of these parameters control the identification efficiency and the accuracy
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
