STABILITY AND DYNAMIC ANALYSIS OF COLD-FORMED STORAGE RACK STRUCTURES WITH SEMIRIGID CONNECTIONS

2011 ◽  
Vol 11 (06) ◽  
pp. 1059-1088 ◽  
Author(s):  
KESHAV K. SANGLE ◽  
KAMAL M. BAJORIA ◽  
RAJSHEKAR S. TALICOTTI
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Buckling Analysis ◽  
Effective Length ◽  
Fundamental Period ◽  
Base Shear ◽  
Element Analysis ◽  
Semirigid Connections ◽  
Dynamic Analyses ◽  
The Impact

This paper presents the finite element buckling and dynamic analyses of two-dimensional (2D) single frames and three-dimensional (3D) frames of cold-formed sections with semirigid connections used in the conventional pallet racking system. The results of buckling analysis for the single 2D frames are compared with those from the experimental study and effective length approach given by RMI. The finite element model used for the single 2D plane frame is further extended to 3D frames with semirigid connections, for which the buckling analysis results are obtained. The buckling and dynamic analyses are carried out using ANSYS for 18 types of developed column sections. The stiffness of the semirigid connection is determined by both the single and double cantilever test methods, along with the nonlinear finite element analysis. Further, an equivalent single degree-of-freedom model is proposed for simulating the seismic behavior of the storage rack in the down-aisle direction, aimed at developing simplified equations for the fundamental period, base shear, and top displacement of the rack. A parametric study is carried out to compute the fundamental period and mode shape. The transient dynamic analysis is also performed for evaluating the impact of the forklift on columns of the frame.

Buckling Analysis of Sway Steel Frames with Semi-Rigid Connections

2011 ◽  
Vol 250-253 ◽  
pp. 3876-3879
Author(s):  
Wan Zhen Wang ◽  
Ji Xiang Xu ◽  
Fei Yi Chen
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Steel Frames ◽  
Buckling Analysis ◽  
Nonlinear Finite Element ◽  
Effective Length ◽  
Finite Element Models ◽  
Rotational Stiffness ◽  
Element Analysis ◽  
Effective Length Factor

The modified factor formulas, which are applicable to sway steel frames, are derived by considering joint relative rotational stiffness and adopting the modified stiffness factor. The finite element models of steel frames with semi-rigid and rigid connections are established using ANSYS program. Nonlinear finite element analysis of steel frames with two web and top-seat angles steel semi-rigid connections is conducted. Through bulking analysis of sway steel frames with semi-rigid connections, the effective length factor of sway steel frames is derived, which considers nonlinear rotation of two web and top-seat angles steel semi-rigid connections.

scholarly journals BEHAVIOUR OF PARALLEL GIRDERS STABILISED WITH U‐FRAMES

2010 ◽  
Vol 16 (2) ◽  
pp. 197-202 ◽  
Author(s):  
Kuldeep Virdi ◽  
Walid Azzi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Buckling Analysis ◽  
Effective Length ◽  
Ultimate Capacity ◽  
Lateral Torsional Buckling ◽  
Torsional Buckling ◽  
Element Analysis ◽  
Key Factor ◽  
The Stability

Lateral torsional buckling is a key factor in the design of steel girders. Stability can be enhanced by cross‐bracing, reducing the effective length and thus increasing the ultimate capacity. U‐frames are an option often used to brace the girders, when designing through type of bridges and where overhead bracing is not practical. This paper investigates the effect of the U‐frame spacing on the stability of the parallel girders. Eigenvalue buckling analysis was undertaken with four different spacings of the U‐frames. Results were extracted from finite element analysis, interpreted and conclusions drawn. Santrauka Projektuojant plienines sijas šoninis sukamasis klupumas yra svarbiausias veiksnys. Pastovumas gali būti padidintas skersiniais ryšiais, mažinančiais veikiamaji ilgi ir padidinančiais ribine galia. U‐formiai remai yra dažna priemone sijoms išramstyti, kai projektuojami tiltai, kuriu laikančiosios konstrukcijos yra virš pakloto, o viršutiniai ryšiai yra nepraktiški. Šiame straipsnyje nagrinejamas U‐formiu remu tarpatramio poveikis lygiagrečiuju siju pastovumui. Tikravertis klupumo skaičiavimas buvo atliktas esant keturiems skirtingiems U‐formiu remu tarpatramiams. Aptarti rezultatai, gauti apskaičiavus baigtinius elementus, padarytos išvados.

scholarly journals A Technique for Dynamic Analyses of Containers With Locking-Ring Closures

2002 ◽  
Author(s):  
Tsu-te Wu
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Complex Structure ◽  
Ring Closure ◽  
Dynamic Responses ◽  
Explicit Method ◽  
Element Analysis ◽  
Explicit Finite Element ◽  
The Finite Element Analysis ◽  
Dynamic Analyses

The explicit method of the finite-element analysis is capable of analyzing the dynamic responses of a complex structure with complicated contact conditions. The method has been widely used in evaluating the dynamic responses of shipping package for radioactive materials. However, the previous analyses focused on the stresses and deformations of the structure components subjected impact loads and the possibility of the locking-ring closure separating from the drum body is not accounted for. The major difficulty for applying the explicit method to a container with a locking-ring closure is that the phenomenon of pre-loading a locking-ring closure is a static process; whereas, the explicit method involves the propagation of stress waves in the structure and thus is only applicable to dynamic analyses. The purpose of the present paper is to propose a technique that extends the application of the explicit finite-element method to the dynamic analysis of the container pre-loaded by a lock-ring. Unlike the conventional dynamic analysis by the explicit method that only needs one load step, the proposed technique requires three sequential procedure steps (not load steps) to complete an entire analysis. Furthermore, one procedure step may consist of two load steps. The paper discusses the procedures of the proposed technique in details. The application of the technique is illustrated by an example problem. The adequacy of the technique is also verified.

The Research of the Impact of Dynamic Analysis from the Stiffness of the Light Steel Floor of the Steel Frame

2013 ◽  
Vol 772 ◽  
pp. 47-51
Author(s):  
Chun Xia Gong ◽  
Cao Xi
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Steel Frame ◽  
Frame Structure ◽  
Element Analysis ◽  
Calculation Results ◽  
Set Up ◽  
Frame Set ◽  
Steel Frame Structure ◽  
The Impact

This paper uses ANSYS10.0 to make modal analysis of the finite element models of the light steel frame. Set up two finite element analysis models with different stiffness of floor, one with the rigid floor assumption, another kind with the light steel floor,so as to research the influence of the calculation results of dynamic analysis. According to the analysis results,we can get that how to define the stiffness of floor is more accurate when design the light steel frame structure. So that to provide the theoretical basis for the designing of light steel frame constructions.

scholarly journals Potential and limitations of finite element modelling in assessing structural integrity of coralline algae under future global change

2015 ◽  
Vol 12 (19) ◽  
pp. 5871-5883 ◽  
Author(s):  
L. A. Melbourne ◽  
J. Griffin ◽  
D. N. Schmidt ◽  
E. J. Rayfield
Keyword(s):  
Climate Change ◽  
Finite Element ◽  
Structural Integrity ◽  
Geometric Model ◽  
Algal Growth ◽  
Coralline Algae ◽  
Rocky Shores ◽  
Element Analysis ◽  
Scan Data ◽  
The Impact

Abstract. Coralline algae are important habitat formers found on all rocky shores. While the impact of future ocean acidification on the physiological performance of the species has been well studied, little research has focused on potential changes in structural integrity in response to climate change. A previous study using 2-D Finite Element Analysis (FEA) suggested increased vulnerability to fracture (by wave action or boring) in algae grown under high CO2 conditions. To assess how realistically 2-D simplified models represent structural performance, a series of increasingly biologically accurate 3-D FE models that represent different aspects of coralline algal growth were developed. Simplified geometric 3-D models of the genus Lithothamnion were compared to models created from computed tomography (CT) scan data of the same genus. The biologically accurate model and the simplified geometric model representing individual cells had similar average stresses and stress distributions, emphasising the importance of the cell walls in dissipating the stress throughout the structure. In contrast models without the accurate representation of the cell geometry resulted in larger stress and strain results. Our more complex 3-D model reiterated the potential of climate change to diminish the structural integrity of the organism. This suggests that under future environmental conditions the weakening of the coralline algal skeleton along with increased external pressures (wave and bioerosion) may negatively influence the ability for coralline algae to maintain a habitat able to sustain high levels of biodiversity.

Response of Mild Steel Pipes Under High Mass Low Velocity Impacts

2014 ◽  
Author(s):  
Shamsoon Fareed ◽  
Ian May
Keyword(s):  
Finite Element ◽  
Mild Steel ◽  
Impact Energy ◽  
High Mass ◽  
Low Velocity ◽  
Element Analysis ◽  
Steel Pipes ◽  
Impact Tests ◽  
The Finite Element Analysis ◽  
The Impact

Accidental loads, for example, due to heavy dropped objects, impact from the trawl gear and anchors of fishing vessels can cause damage to pipelines on the sea bed. The amount of damage will depend on the impact energy. The indentation will be localized at the contact area of the pipe and the impacting object, however, an understanding of the extent of the damage due to an impact is required so that if one should occur in practice an assessment can be made to determine if remedial action needs to be taken to ensure that the pipeline is still serviceable. There are a number of parameters, including the pipe cross section and impact energy, which influence the impact behaviour of a pipe. This paper describes the response, and assesses the damage, of mild steel pipes under high mass low velocity impacts. For this purpose full scale impacts tests were carried out on mild steel pipe having diameter of 457 mm, thickness of 25.4 mm and length of 2000 mm. The pipe was restrained along the base and a 2 tonnes mass with sharp impactor having a vertical downward velocity of 3870 mm/sec was used to impact the pipe transversely with an impact energy of 16 kJ. It was found from the impact tests that a smooth indentation was produced in the pipe. The impact tests were then used for validation of the non-linear dynamic implicit analyses using the finite element analysis software ABAQUS. Deformations at the impact zone, the rebound velocity, etc, recorded in the tests and the results of the finite element analysis were found to be in good agreement. The impact tests and finite element analyses described in this paper will help to improve the understanding of the response of steel pipes under impact loading and can be used as a benchmark for further finite element modelling of impacts on pipes.

Flexible Flowline Walking Tendency on Seabed With Longitudinal Undulations and Transverse Gradients

2018 ◽  
Author(s):  
Graeme Roberts ◽  
T. Sriskandarajah ◽  
Gianluca Colonnelli ◽  
Arnaud Roux ◽  
Alan Roy ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Temperature Gradients ◽  
Radius Of Curvature ◽  
Bend Radius ◽  
Lateral Buckling ◽  
Element Analysis ◽  
Slip Tendency ◽  
Start Ups ◽  
The Impact

A method of carrying out a combined axial walking and lateral buckling assessment for a flexible flowline has been developed using finite element analysis. The method overcomes limitations of screening assessments which could be inconclusive when applied either to a flexible flowline on an undulating seabed with transverse gradients or to one that buckles during hydrotest. Flexible flowlines that were to be surface-laid on a seabed with longitudinal undulations and transverse gradients were assessed using the method. The flexible flowlines were simulated in their as-laid state, and the simulation incorporated hydrotest pressure and the pressure & temperature gradients and transients associated with multiple start-ups. The objective was to quantify the axial walking and lateral slip tendency of the flexible flowlines and the impact that walking might have on the connected end structures. The lateral buckle locations predicted by finite element analysis were compared to a post-hydrotest survey and the radius of curvature from analysis was compared to the minimum bend radius of the flexible.

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