It is empirically established that, due to a number of factors involved, a classical (linear) analysis of buckling pressure is impossible. Nonlinear theories of buckling are, therefore, required that involve effective factors such as imperfections and welding effects. In this study, models are developed which are as close to allowable standard deviations as possible. In the next stage, their bu...

Thin plates are subject to several imperfections (including dents) which reduce the ultimate strength of plates. In this work, nearness effect of two short dents of same size on the ultimate strength of a thin square steel plate is numerically investigated. Dents are modeled on the FE surface of the undented plate by varying the location and orientation of dents and the centre distance between ...

Buckling and wrinkling of thin structures often lead to very complex response curves that are hard follow by standard path-following techniques, especially for membranes in a slack or nearly state. Many recent papers mention numerical difficulties encountered the treatment problems, with procedures these authors switch pseudo-dynamic algorithms. Moreover, modeling many wrinkles leads large size...

An efficient beam element, the modified elastofiber (MEF) element, has been developed to capture the overall features of the elastic and inelastic response of slender columns and braces under axial cyclic loading without unduly heavy discretization. It consists of three fiber segments, two at the member ends and one at mid-span, with two elastic segments sandwiched in between. The segments are ...

PANDA2, a computer program for the minimum-weight design of elastic perfect and imperfect stiffened cylindrical panels and shells under multiple sets of combined loads, is used to obtain optimum designs of uniformly axially compressed elastic internal T-ring and external T-stringer stiffened cylindrical shells with initial imperfections in the form of the general buckling mode. The optimum desi...

Conventional concentrically-braced frame (CBF) systems have limited drift capacity before brace buckling and related damage leads to deterioration in strength and stiffness. Self-centering concentrically-braced frame (SC-CBF) systems have been developed to increase drift capacity prior to initiation of damage and minimize residual drift. SC-CBFs differ from conventional CBFs in that the SC-CBF ...

The present study investigates buckling characteristics of both nonlinear symmetric power and sigmoid functionally graded (FG) beams. The volume fractions of metal and ceramic are assumed to be distributed through a beam thickness by the sigmoid-law distribution (S-FGM), and the symmetric power function (SP-FGM). These functions have smooth variation of properties across the boundary rather tha...

Abstract A cylindrical hydrogel tube, completely submerged in water, hydrates by swelling and filling its internal cavity. When it comes back into contact with air, dehydrates: the tube thus expels solvent through walls, shrinking. This dehydration process causes a depression cavity, which can lead to circumferential buckling. Here we study occurrence of such buckling using continuous model tha...

In this study, the method of multiple scales is used to perform a nonlinear vibration analysis of a mechanical system in two cases; with dry and lubricated clearance joints. In the dry contact case, the Lankarani-Nikravesh model is used to represent the contact force between the joined bodies. The surface elasticity is modeled as a nonlinear spring-damper element. Primary resonance is discussed...