Significance Of Distortion Research Articles

Theoretical and Experimental Analysis of Thin-Walled Curved Rectangular Box Beam under In-Plane Bending.

Thin-walled curved box beam structures especially rectangular members are widely used in mechanical and architectural structures and other engineering fields because of their high strength-to-weight ratios. In this paper, we present experimental and theoretical analysis methods for the static analysis of thin-walled curved rectangular-box beams under in-plane bending based on 11 feature deformation modes. As to the numerical investigations, we explored the convergence and accuracy analysis by normal finite element analysis, higher-order assumed strain plane element, deep collocation method element, and inverse finite element method, respectively. The out-of-plane and in-plane characteristic deformation vector modes derived by the theoretical formula are superimposed by transforming the axial, tangential, and the normal deformation values into scalar tensile and compression amounts. A one-dimensional deformation experimental test theory is first proposed, formulating the specific contributions of various deformation modes. In this way, the magnitude and trend of the influence of each low-order deformation mode on the distortion and warping in the actual deformation are determined, and the significance of distortion and warping in the actual curved beams subjected to the in-plane loads is verified. This study strengthens the deformation theory of rectangular box-type thin-walled curved beams under in-plane bending, thus providing a reference for analyzing the mechanical properties of curved-beam structures.

Significance of distortion in thin-walled closed beam section design

Torsional and/or bending rigidities have been used as the key performance measure in conventional beam section design practice. The goal of this investigation is, however, to show that a so-called distortional rigidity also affects significantly the section shapes especially in the design of thin-walled closed beam sections. Though several investigations have analyzed complicated deformations of thin-walled beams such as distortion and warping, this paper is perhaps the first report to show how the design of thin-walled beam section shapes is affected by the additional consideration of the distortional rigidity. To illustrate this, several beam section optimization problems are considered.

Parameters Affecting Distortional Buckling of Tapered Steel Members

A finite‐element method of analysis for the elastic distortional buckling of doubly symmetric tapered I‐section beam‐columns has been modified to consider the effects of off‐shear center loading and discrete elastic restraints applied anywhere in the cross section or along the length of the beam‐column. The accuracy of the finite‐element method is demonstrated for prismatic members by a comparison with closed‐form solutions, or numerical solutions for which no closed‐form solution exists. Discrepancies in some other well‐cited formulations are discussed with reference to this model. The method is then used to investigate the significance of distortion in the buckling of I‐section plate girders typical of those comprising fabricated industrial roofs, considering the restraining effects of the purlins and the loading being remote from the shear center.