Effect of Cross Sectional Shape on the Energy Absorbing Characteristics of a Tube under Quasi-Static Loading

2013 ◽  
Vol 315 ◽  
pp. 334-338 ◽  
Author(s):  
Jaffar S. Mohamed Ali ◽  
Kassim A. Abdullah ◽  
Yulfian Aminanda
Keyword(s):  
Energy Absorption ◽  
Axial Compression ◽  
Cross Section ◽  
Cross Sections ◽  
Cross Sectional ◽  
Tube Cross Section ◽  
Deformation Response ◽  
Section Shape ◽  
Energy Absorbing ◽  
Sectional Shape

In this study, numerical simulation of tubes of various cross section under axial compression is carried out using LS-DYNA. The effect of varying configurations of tube cross-section shape on the deformation response, collapse mode and energy absorption characteristics of tubes under quasi-static axial compression have been studied. The validation of the finite element tube model was made by comparison with the experimental results of the square tube subjected to quasi-static axial compression. Tabulated results are presented and plots have been included for the specific energy absorption for different cross sections. The study provides an insight on ways to increasing energy absorption of light weight aluminium tubes.

Automated 3D measurement of fiber cross section morphology in handsheets

2012 ◽  
Vol 27 (2) ◽  
pp. 264-269 ◽  
Author(s):  
Christian Lorbach ◽  
Ulrich Hirn ◽  
Johannes Kritzinger ◽  
Wolfgang Bauer
Keyword(s):  
Image Analysis ◽  
Cross Section ◽  
Cross Sections ◽  
Image Plane ◽  
3D Measurement ◽  
Cross Sectional ◽  
Fiber Cross Section ◽  
Fiber Wall ◽  
Sectional Shape ◽  
Cross Section Geometry

Abstract We present a method for 3D measurement of fiber cross sectional morphology from handsheets. An automated procedure is used to acquire 3D datasets of fiber cross sectional images using an automated microtome and light microscopy. The fiber cross section geometry is extracted using digital image analysis. Simple sample preparation and highly automated image acquisition and image analysis are providing an efficient tool to analyze large samples. It is demonstrated that if fibers are tilted towards the image plane the images of fiber cross sections are always larger than the true fiber cross section geometry. In our analysis the tilting angles of the fibers to the image plane are measured. The resulting fiber cross sectional images are distorted to compensate the error due to fiber tilt, restoring the true fiber cross sectional shape. We use an approximated correction, the paper provides error estimates of the approximation. Measurement results for fiber wall thickness, fiber coarseness and fiber collapse are presented for one hardwood and one softwood pulp.

Cross Section Optimization of Plane Truss among Different Spans

2014 ◽  
Vol 679 ◽  
pp. 1-5 ◽  
Author(s):  
Sumayah Abdulsalam Mustafa ◽  
Mohd Zulham Affandi bin Mohd Zahid ◽  
Md.Hadli bin Abu Hassan
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Element Analysis ◽  
Cross Sectional ◽  
Analysis And Design ◽  
Cross Section Shape ◽  
Design Variables ◽  
Section Shape ◽  
Steel Sections ◽  
Research Show

Cross sectional areas optimization is to be implemented to study the influence of the cross section shape on the optimum truss weight. By the aid of analysis and design engines with advanced finite element analysis that is the steel design software STAAD. Four rolled steel sections (angle, tube, channel, and pipe) which are used in industrial roof trusses are applied for comparison. Many previous studies, use the areas of cross sections as design variables without highlight to the shape of cross section at the start of the process, consequently the result area will be adequate if the designer choose the effective shape than others. Results of this research show that the chosen cross section shape has a significant impact on the optimum truss weight for same geometry of truss type under the same circumstances of loading and supports.

Bounds on the Maximum Thermoelastic Stress and Deflection in a Beam and Plate

1966 ◽  
Vol 33 (4) ◽  
pp. 881-887 ◽  
Author(s):  
Bruno A. Boley
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Practical Interest ◽  
Thermoelastic Stress ◽  
Cross Sectional ◽  
Special Cases ◽  
End Conditions ◽  
Instantaneous Temperature ◽  
The Cross ◽  
Sectional Shape

It is shown in this paper that the thermal stress in a beam or plate cannot exceed the value kαEΔT, where ΔT is the maximum instantaneous temperature excursion in a cross section, and k is a coefficient dependent on the shape of the cross section. A simple general formula for k is found, and results for several special cases of practical interest are given. For rectangular beams (suitably oriented) and for plates, for example, k = 4/3. For any section, k = 1 if the thermal moment is zero; simplifications also occur if the thermal force is zero. The corresponding results for beam deflections are also carried out: The maximum deflection cannot exceed the value kδ kδ′αLΔT, where kδ and kδ′ are coefficients depending respectively on the cross-sectional shape and on the end conditions. For example, for rectangular cross sections, kδ = 3/4; and for a simply supported beam, kδ′ = 1/8.

Influence of the Cross Section Shape on Energy Absorbing Component of Bumper Subjected to Low Speed Crash

2013 ◽  
Vol 477-478 ◽  
pp. 3-6
Author(s):  
Yan Jie Liu ◽  
Lin Ding
Keyword(s):  
Energy Absorption ◽  
Cross Section ◽  
Peak Load ◽  
Low Velocity Impact ◽  
Fe Model ◽  
Cross Section Shape ◽  
Section Shape ◽  
The Cross ◽  
Energy Absorbing ◽  
The Impact

Energy absorbing component of bumper equipped at the front end of a car, is one of the most important automotive parts for crash energy absorption. It usually was made a mental thin walled tube. In the paper, automobile energy absorbing component at low-velocity impact was studied by using Finite Element Method. The FE model of the tube was builded by comparing the five cross section shape . Results show that the impact peak load and maximum energy absorption have certain effect to energy-absorbing component with different the cross section shape.

Cushioning energy absorption of paper corrugation tubes with regular polygonal cross-section under axial static compression

2021 ◽  
Vol 28 (1) ◽  
pp. 24-38
Author(s):  
Jianfen Kang ◽  
Yanfeng Guo ◽  
Yungang Fu ◽  
Qiong Li ◽  
Yabo Lv
Keyword(s):  
Energy Absorption ◽  
Cross Section ◽  
Failure Modes ◽  
Unit Area ◽  
Deformation Mode ◽  
Tube Length ◽  
Cross Sectional ◽  
Static Compression ◽  
Regular Triangle ◽  
Sectional Shape

Abstract The paper corrugation tube is an innovative kind of energy absorbing structure and shock absorber which can play an important role on the cushioning energy absorption for airdrop equipments and transportation packaging. The deformation characteristics and failure modes of the regular triangle, quadrangle, pentagon and hexagon paper corrugation tubes were comparatively studied by a series of axial static compression experiments, the cushioning energy absorption was evaluated by the seven characteristic parameters (e.g. initial peak force, mean crush force, total energy absorption, specific energy absorption, crush force efficiency, unit area energy absorption and stroke efficiency), and the influences of tube direction, cross-sectional shape, tube length and compression rate on failure modes and cushioning energy absorption were analyzed and compared. These researches showed that the tubes along X direction only have the accordion deformation mode, yet the tubes along Y direction have four deformation modes including steady state progressive buckling, Euler buckling, angular tear and transverse shear. For the paper corrugation tubes along Y direction, the cross-sectional shape has obvious influence on the cushioning energy absorption of structures, and the specific energy absorption and unit area energy absorption of regular triangle and pentagon tubes are better than those of the tubes with regular quadrilateral and hexagonal cross-section at compression rates of 12 and 48mm/min. The tube length of 150 mm or compression rate of 72 mm/min would cause the increase of contribution proportion of non-ideal deformation mode and the decrease of cushioning properties. The paper corrugation tubes along X direction have more stable and controllable deformation mode, yet the paper corrugation tubes along Y direction have better cushioning energy absorption.

Design of C-Frames Using Real-Coded Genetic Optimization Algorithms and NURBS

1999 ◽  
Author(s):  
Ashraf O. Nassef ◽  
Hesham A. Hegazi ◽  
Sayed M. Metwalli
Keyword(s):  
Genetic Algorithms ◽  
Cross Section ◽  
Cross Sections ◽  
Design Parameters ◽  
Binary Representation ◽  
Cross Sectional ◽  
Search Spaces ◽  
The Cross ◽  
Sectional Shape ◽  
Real Coded Genetic Algorithms

Abstract C-frames constitute a large portion of machine tools that are currently used in industry. Examples of these frames include drilling machines, presses, punching and stamping machines, clamps, hooks, etc. The design parameters of these frames include the dimensions of their cross-sections, which should be chosen to withstand the applied loads and minimize the element’s overall weight. Traditionally, the cross-section of C-frame belonged to a set of primitive shapes, which included I, T, trapezoidal and rectangular sections. This paper introduces a new methodology for designing the frame’s cross-section. The cross-sectional shape is represented using non-uniform rational B-Spline (NURBS) in order to give it a form of shape flexibility. A special form of genetic algorithms known as real-coded genetic algorithms is used to conduct the search for the design objectives. Real-coded genetic algorithms are known to outperform the simple binary representation genetic algorithms when dealing with continuous search spaces. The results showed that the optimal shape was a semi I/T-section with the material bulk related to the applied load.

Characterization Method for Shape Factor of the Hollow-Triangle Fiber

2012 ◽  
Vol 441 ◽  
pp. 736-740 ◽  
Author(s):  
Shun Hua Zhang ◽  
Hai Xia Wu ◽  
Li Na Zhang ◽  
Xiao Xiao Liu
Keyword(s):  
Cross Section ◽  
Hollow Fiber ◽  
Shape Factor ◽  
Equivalent Diameter ◽  
Cross Sectional ◽  
Shape Factors ◽  
Shape Coefficient ◽  
Section Shape ◽  
Image Acquisition System ◽  
Sectional Shape

The hollow-triangle fiber is a novel profiled fiber. Its cross-sectional shape and shape factor index were obtained by a microcomputer image acquisition system, with a polarization capability and image analysis software. The shape factors of the fiber, such as shape factor in radius, shape factor in cross-section, branch factor and volume content were tested. The cross-section shape of cross-hollow fiber was compared with that of the hollow fiber. After that, a novel method about equivalent diameter was proposed to evaluate the characteristic shape coefficient. The method possesses many merits such as rapid, simple, accurate, convenient and thus being of great practical value.

Deformation and Energy Absorption Characteristics of Thin-Walled Structures

2009 ◽  
Author(s):  
Ahmed Elmarakbi ◽  
Niki Fielding
Keyword(s):  
Energy Absorption ◽  
Peak Load ◽  
Cross Sectional ◽  
Explicit Finite Element ◽  
Thin Walled Structures ◽  
Column Structure ◽  
Axial Crush ◽  
Energy Absorbing ◽  
Sectional Shape ◽  
Vehicle Crashworthiness

In this paper, to investigate the design of an energy absorbing street pole, a study of axial crush behaviour of metal thin longitudinal tubes (columns) are investigated along with a number of variables such as cross-sectional shape, shell thickness, as well as the velocity affects on columns. Tests have been carried out on the effects of bedded crumple initiators placed a various heights from the top of the column, in determining the desired value of peak load reduction, along with the effect in energy absorption of the column. With the conclusion of the desired variables for the design of an energy absorbing column, the columns are placed 90 degrees to that of the base of the model street column. Simulation of frontal impact of a vehicle and street column are analysed and compared to that of the energy absorbing street column concept. Studies are carried out by numerical simulation via the explicit finite element code LS-DYAN. Results compare the absorbed energy and the deflection of each variable, and recommend best design for the column structure which improved vehicle crashworthiness.

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