in this paper, the behavior of free vibrations and buckling of the sandwich panel with a flexible core was investigated using a new improved ‎high-order sandwich panel theory. in this theory, equations of motion were formulated based on shear stresses in the core. first-order shear deformation theory was ‎applied for the procedures. in this theory, for the first time, incompatibility problem of...

Treated herein is the elastic buckling problem of Single-Walled Carbon Nanotubes (SCNTs) under axial compression. Critical buckling strains cr ε of stocky SCNTs (length/diameter less than 8) that have been obtained by modeling them as first-order shear deformation (thick) shell theory (FSDST). The buckling strains are compared with those obtained by commonly used thin shell theories, such as th...

Level-set topology optimization is used to design a wing considering skin buckling under static aeroelastic trim loading, as well as dynamic aeroelastic stability (flutter). The level-set function is defined over the entire 3D volume of a transport aircraft wing box. Therefore, the approach is not limited by any predefined structure and can explore novel configurations. The Sequential Linear Pr...

The equivalent force control (EFC) method replaces numerical iteration with a feedback control strategy to solve the nonlinear equations of motion in pseudodynamic and real-time substructure tests (RST) using an implicit integration method. The EFC method and its further development with an energy conserving integration method are presented in this paper. The effectiveness and accuracy of the E...

This work develops a framework for SIMP-based topology optimization of a metallic panel structure subjected to design-dependent aerodynamic, inertial, elastic, and thermal loads. Multi-physics eigenvalue-based design metrics such as thermal buckling and dynamic flutter are derived, along with their adjoint-based design derivatives. Locating the flutter point (Hopf-bifurcation) in a precise and ...

This paper is concerned with the buckling of double-walled carbon nanotubes (DWCNTs) under axial load. The DWCNTs are modelled as two cylindrical shells, one shell nested in the other and Winkler springs are introduced to connect them in order to simulate the van der Waals forces between the two nanotubes. By using the Donnell thin shell theory, we derive the governing equations for the bucklin...

The crush behaviors of steel tubes filled with nanoporous-materials-functionalized liquids are experimentally investigated under quasi-static and dynamic conditions. Results show that the nanoporous-materials-functionalized liquid can enhance the load-carrying and the energy absorption capacities of thin-walled tubes, as the buckling mode is affected. The effective buckling stress increases wit...

The dynamic buckling of thin isotropic thermoviscoplastic cylindrical shells compressed with a uniform axial velocity prescribed at the end faces is investigated analytically and numerically. In the first part of the paper, the stressed/deformed state of a shell is assumed to have buckled if infinitesimal perturbations superimposed upon it grow. Cubic algebraic equations are derived for both th...