A one-dimensional theory of thin-walled curved rectangular box beams under torsion and out-of-plane bending

2002 ◽  
Vol 53 (7) ◽  
pp. 1675-1693 ◽  
Author(s):  
Yoon Young Kim ◽  
Youngkyu Kim
Keyword(s):  
Dimensional Theory ◽  
One Dimensional ◽  
Out Of Plane ◽  
Box Beams ◽  
Thin Walled ◽  
Plane Bending

Exact Matching Condition at a Joint of Thin-Walled Box Beams Under Out-of-Plane Bending and Torsion

2012 ◽  
Vol 79 (5) ◽  
Author(s):  
Soomin Choi ◽  
Gang-Won Jang ◽  
Yoon Young Kim
Keyword(s):  
Beam Theory ◽  
Matching Condition ◽  
Higher Order ◽  
Transformation Matrix ◽  
Exact Matching ◽  
Box Beam ◽  
Out Of Plane ◽  
Box Beams ◽  
Thin Walled ◽  
Plane Bending

To take into account the flexibility resulting from sectional deformations of a thin-walled box beam, higher-order beam theories considering warping and distortional degrees of freedom (DOF) in addition to the Timoshenko kinematic degrees have been developed. The objective of this study is to derive the exact matching condition consistent with a 5-DOF higher-order beam theory at a joint of thin-walled box beams under out-of-plane bending and torsion. Here we use bending deflection, bending/shear rotation, torsional rotation, warping, and distortion as the kinematic variables. Because the theory involves warping and distortion that do not produce any force/moment resultant, the joint matching condition cannot be obtained just by using the typical three equilibrium conditions. This difficulty poses considerable challenges because all elements of the 5×5 transformation matrix relating the field variables of one beam to those in another beam should be determined. The main contributions of the investigation are to propose additional necessary conditions to determine the matrix and to derive it exactly. The validity of the derived joint matching transformation matrix is demonstrated by showing good agreement between the shell finite element results and those obtained by the present box beam analysis in various angle box beams.

Stresses in Curved, Circular Thin-Wall Tubes

1963 ◽  
Vol 30 (1) ◽  
pp. 134-135
Author(s):  
E. A. Utecht
Keyword(s):  
Thin Wall ◽  
Bending Moments ◽  
Circular Tubes ◽  
Out Of Plane ◽  
Thin Walled ◽  
Plane Bending

Curves are presented which give stress intensification factors for curved, thin-walled circular tubes under various combinations of in-plane and out-of-plane bending moments.

Stress and flexibility factors for multi-mitred pipe bends subjected to internal pressure combined with external loadings

1972 ◽  
Vol 7 (2) ◽  
pp. 97-108 ◽  
Author(s):  
M P Bond ◽  
R Kitching
Keyword(s):  
Internal Pressure ◽  
Large Diameter ◽  
Pipe Bend ◽  
Bending Tests ◽  
Bending Load ◽  
Out Of Plane ◽  
Thin Walled ◽  
Plane Bending ◽  
Internal Pressures ◽  
Stress Patterns

The stress analysis of a multi-mitred pipe bend when subjected to an internal pressure and a simultaneous in-plane or out-of-plane bending load has been developed. Stress patterns and flexibility factors calculated by this analysis are compared with experimental results from a large-diameter, thin-walled, three-weld, 90° multi-mitred bend which was subjected to in-plane bending tests at various internal pressures.

Bend Flexibility Factors of Piping Elbows and Piping Elbows With Trunnion Attachments Using the Boundary Element Method

2009 ◽  
Author(s):  
Manuel Martinez ◽  
Johane Bracamonte ◽  
Marco Gonzalez
Keyword(s):  
Boundary Element Method ◽  
Numerical Method ◽  
Bending Moment ◽  
Piping System ◽  
Thin Walled Structures ◽  
Out Of Plane ◽  
Thin Walled ◽  
Plane Bending ◽  
Flexibility Factor ◽  
Element Method

Flexibility Factor is an important parameter for the design of piping system related to oil, gas and power industry. Elbows give a great flexibility to piping system, but where a trunnion is attached to an elbow in order to support vertical pipe sections, the piping flexibility is affected. Generally, determination of elbow flexibility factors has been performed by engineering codes such as ASME B31.3 or ASME B31.8, or using the Finite Element Method (FEM) and Finite Difference Method (FDM). In this work, bend flexibility factors for 3D models of piping elbows and piping elbows with trunnion attachments using the Boundary Element Method (BEM) are calculated. The BEM is a relatively new numerical method for this kind of analysis, for which only the surface of the problem needs to be discretized into elements reducing the dimensionality of the problem. This paper shows the simulation of 9 elbows with commercially available geometries and 29 geometries of elbows with trunnion attachments, 10 of them using commercial elbow dimensions, with applied in-plane and out-of-plane bending moments. Structured meshes are used for all surfaces, except the contact surface of elbow-trunnion joints, and no welded joints are simulated. The results show smaller values of flexibility factors of elbow and elbow–trunnion attachments in all loading cases if are compared to ASME B31.3 or correlations obtained from other works. The results also indicate that flexibility factor for elbow-trunnion attachment subjected to in-plane bending moment is greater than flexibility factor for out-of plane bending moment. Accuracy of BEM’s results were not good when flexibility characteristic values are lesser than 0.300, which confirm the problems of this numerical method with very thin-walled structures. The method of limit element could be used as tool of alternative analysis for the design of made high-pitched system, when the problem with very thin-walled structures is fixed.

Analysis of thin-walled frames considering joint flexibilities

2007 ◽  
Vol 221 (10) ◽  
pp. 1221-1229 ◽  
Author(s):  
P R Marur
Keyword(s):  
Beam Theory ◽  
Frame Structure ◽  
Elastic Response ◽  
Joint Flexibility ◽  
One Dimensional ◽  
Static And Dynamic Analysis ◽  
Out Of Plane ◽  
Thin Walled ◽  
Shell Finite Element ◽  
Good Agreement

TAnalytical models are developed for static and dynamic analysis of thin-walled frames representing the automotive side structures. The model is based on one-dimensional beam theory that considers joint flexibility to compute stiffness and frequency response of the whole frame structure. The computed out-of-plane displacements under static and impact loading are in good agreement with those obtained from the shell finite element method. Using the validated analytical model, the influence of joint flexibility on the elastic response of the side structure is studied.

Thin-Walled Multicell Beam Analysis for Coupled Torsion, Distortion, and Warping Deformations

2000 ◽  
Vol 68 (2) ◽  
pp. 260-269 ◽  
Author(s):  
J. H. Kim ◽  
Y. Y. Kim
Keyword(s):  
Shear Flows ◽  
Systematic Approach ◽  
Beam Theory ◽  
Warping Function ◽  
Dimensional Theory ◽  
One Dimensional ◽  
Superior Result ◽  
Beam Analysis ◽  
Thin Walled

Due to the complicated deformations occurring in thin-walled multicell beams, no satisfactory one-dimensional beam theory useful for general quadrilateral multicells appears available. In this paper, we present a new systematic approach to analyze the coupled deformations of torsion, distortion, and the related warping. To develop a one-dimensional thin-walled multicell beam theory, the method to determine the section deformation functions associated with distortion and distortional warping is newly developed. In order to guarantee the singlevaluedness of the distortional warping function in multicells, distortional shear flows have been utilized. The superior result by the present one-dimensional theory is demonstrated with various examples.

Stress and flexibility factors for multi-mitred bends subjected to out-of-plane bending

1971 ◽  
Vol 6 (4) ◽  
pp. 213-225 ◽  
Author(s):  
M P Bond ◽  
R Kitching
Keyword(s):  
Theoretical Analysis ◽  
Maximum Stress ◽  
Large Diameter ◽  
Stress Distributions ◽  
Factors Associated ◽  
Out Of Plane ◽  
Thin Walled ◽  
Plane Bending ◽  
Stress Ratios

A theoretical analysis has been developed to predict stress distributions and flexibility factors associated with out-of-plane bending of multi-mitred pipe bends. The estimated range of validity of the analysis is sufficient to include most practical multi-mitred pipe bends. Tests on a large-diameter, thin-walled, three-weld right-angled multi-mitred bend were undertaken and the results closely agreed with computations based on the analysis. Predictions for both flexibility factors and overall maximum-stress ratios from the analysis were almost identical with those given by an in-plane bending theory that had been developed from a similar method of approach.

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