scholarly journals Compactness Effect on Bending Behavior of Cold Formed Steel Beams

2020 ◽  
Author(s):  
Zeynep Yaman ◽  
Elif Ağcakoca
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Parametric Study ◽  
Experimental Tests ◽  
Steel Beams ◽  
Collapse Mechanism ◽  
Finite Element Models ◽  
Cross Sectional ◽  
Steel Members ◽  
The Moment

With respect to the determination of the strength of the structural steel members, first the behavior of cross section and then that of the overall member should be considered. In this study, it is aimed to determine the compactness behavior of U-shaped steel sections that exposed to minor-axis bending. Thus, the study questions whether the U-shaped cross section exhibits sufficient dimensions for the collapse mechanism to occur by aiding the moment redistribution in the structural system by supplying sufficient hinge rotation capacity. In order to investigate compactness behavior, three different channel section steel profiles are selected. Four point experimental tests are carried out to validate finite element models of the selected profiles. Upon validated finite element models, parametric studies are performed with finite element analyses. In the parametric study two steel classes, different beam lengths and cross-sectional geometries are taken as parameters. At the end of the study the plate slenderness condition required for plastic design calculated based on Eurocode3 is evaluated with the results of parametric study.

Member distortional buckling behaviour of hybrid double-I-box beams

2018 ◽  
Vol 45 (8) ◽  
pp. 605-622 ◽  
Author(s):  
M.S. Deepak ◽  
V.M. Shanthi
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Parametric Study ◽  
Flexural Rigidity ◽  
Numerical Study ◽  
Plate Thickness ◽  
Distortional Buckling ◽  
Study Results ◽  
Box Beams ◽  
The Moment

This paper compiles the experimental and finite-element parametric study on member distortional buckling behaviour of new built-up metal hybrid double-I-box beams (HDIBBs). The cross-section of this built-up beam is unique and looks similar to the shape of a double-I-box fabricated using four channel sections. The flange plates were provided with an intermediate stiffener. In these built-up beams there is more material in the flange portions far away from the horizontal centroidal axis of their cross-section. Hence, there is an increase in the flexural rigidity that enhances the moment capacity of the beam, under major axis bending. The geometry consists of torsionally rigid closed-box web portion that provides high resistance to minor axis lateral-buckling. The varying parameters considered were the ratio of yield stresses of the flange to the web steel plates, the ratio of breadth to the depth of the section, and the flange plate thickness. In the experimental programme, all the HDIBB members failed due to kinds of distortional buckling which was identified by web buckling and flange twist along edges. The results revealed that when flange plate slenderness increases there is a drop in the moment resistance capacity of the beams. The numerical study was performed using ABAQUS software. In comparison, there was good agreement between experimental and numerical results. The validated finite element models were further extended to perform parametric studies on ideal HDIBB models. Both the experimental and parametric study results were compared with the predicted strengths using effective width method equations specified in the Euro code standards EN 3-1-3. It was found that the current Euro code design rules slightly over-estimate the distortional buckling resistance capacity of closed form built-up cold-formed steel members. A new design equation was formulated and recommended for estimating the reduction in distortional buckling moment resistance capacity for HDIBBs.

Axial strength of steel circular hollow section (CHS) X-joints strengthened by flanged larger pipe

2020 ◽  
Vol 47 (3) ◽  
pp. 301-316
Author(s):  
Peter Gerges ◽  
Sameh Gaawan ◽  
Ashraf Osman
Keyword(s):  
Finite Element ◽  
Parametric Study ◽  
Thickness Ratio ◽  
Finite Element Models ◽  
T Joints ◽  
Hollow Section ◽  
Axial Strength ◽  
Structural Joints ◽  
Circular Hollow Section ◽  
Steel Design

In steel design, enhancing the structural joints’ capacity is considered a challenge that faces the designer. This challenge becomes more difficult when it comes to enhancing the capacities of circular hollow section (CHS) joints due to their closed nature that complicates the strengthening process. Recent research related to strengthening T-joints by utilizing two outer hollow ring flanges welded to additional pipe showed that this technique can significantly improve the joints’ strength. In this study, the utilization of this technique is extended for enhancing the axial strength of CHS X-joints. In this regard, a parametric study using finite element models was carried out to investigate the different design aspects that might affect the behavior of strengthened X-joints. The examined parameters included, the ring flange diameter, the stiffening pipe thickness and length for different brace diameter-to-chord diameter ratios and chord diameter to double chord thickness ratio. The results demonstrated that these strengthened X-joints gained significant axial strength that reached up to three times the axial strength of the unstrengthened joints. Guidelines for proper detailing of such strengthening scheme were provided. Finally, an equation that estimates the axial strength of strengthened joints was established based on the achieved results.

Modal Velocity-Based Multiaxial Fatigue Damage Evaluation Using Simplified Finite Element Models

2020 ◽  
Vol 87 (11) ◽  
Author(s):  
Kurthan Kersch ◽  
Elmar Woschke
Keyword(s):  
Finite Element ◽  
Fatigue Damage ◽  
Cross Section ◽  
Multiaxial Fatigue ◽  
Finite Element Models ◽  
Damage Evaluation ◽  
Geometric Factors ◽  
The Relationship ◽  
General Method

Abstract This work proposes a new method for the fatigue damage evaluation of vibrational loads, based on preceding investigations on the relationship between stresses and modal velocities. As a first step, the influence of the geometry on the particular relationship is studied. Therefore, an analytic expression for Euler Bernoulli beams with a non-constant cross section is derived. Afterward, a general method for obtaining geometric factors from finite element (FE) models is proposed. In order to ensure a fast fatigue damage evaluation, strongly simplified FE-models are used for the determination of both factors and measurement locations. The entire method is demonstrated on three mechanical structures and indicates a better compromise between effort and accuracy than existing methods. For all examples, the usage of velocities and geometric factors obtained from simplified FE models enables a sufficient fatigue damage calculation.

Modelling of Rotating Twisted Blades as 1D Continuum

2016 ◽  
Vol 821 ◽  
pp. 183-190
Author(s):  
Jan Brůha ◽  
Drahomír Rychecký
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Beam Theory ◽  
Parameter Tuning ◽  
Finite Element Models ◽  
Cross Sectional ◽  
One Dimensional ◽  
Rayleigh Beam ◽  
Twisted Blade ◽  
Sectional Parameters

Presented paper deals with modelling of a twisted blade with rhombic shroud as one-dimensional continuum by means of Rayleigh beam finite elements with varying cross-sectional parameters along the finite elements. The blade is clamped into a rotating rigid disk and the shroud is considered to be a rigid body. Since the finite element models based on the Rayleigh beam theory tend to slightly overestimate natural frequencies and underestimate deflections in comparison with finite element models including shear deformation effects, parameter tuning of the blade is performed.

scholarly journals Investigation of the Compressive Viscoelastic Properties of Brain Tissue Under Time and Frequency Dependent Loading Conditions

2021 ◽  
Author(s):  
Weiqi Li ◽  
Duncan E. T. Shepherd ◽  
Daniel M. Espino
Keyword(s):  
Finite Element ◽  
Brain Tissue ◽  
Time Domain ◽  
Viscoelastic Properties ◽  
Loss Modulus ◽  
Series Representation ◽  
Experimental Tests ◽  
Finite Element Models ◽  
Frequency Dependent

AbstractThe mechanical characterization of brain tissue has been generally analyzed in the frequency and time domain. It is crucial to understand the mechanics of the brain under realistic, dynamic conditions and convert it to enable mathematical modelling in a time domain. In this study, the compressive viscoelastic properties of brain tissue were investigated under time and frequency domains with the same physical conditions and the theory of viscoelasticity was applied to estimate the prediction of viscoelastic response in the time domain based on frequency-dependent mechanical moduli through Finite Element models. Storage and loss modulus were obtained from white and grey matter, of bovine brains, using dynamic mechanical analysis and time domain material functions were derived based on a Prony series representation. The material models were evaluated using brain testing data from stress relaxation and hysteresis in the time dependent analysis. The Finite Element models were able to represent the trend of viscoelastic characterization of brain tissue under both testing domains. The outcomes of this study contribute to a better understanding of brain tissue mechanical behaviour and demonstrate the feasibility of deriving time-domain viscoelastic parameters from frequency-dependent compressive data for biological tissue, as validated by comparing experimental tests with computational simulations.

scholarly journals Electrical Capacitance Tomography (ECT) Electrode Size Simulation Study for Cultured Cell

2021 ◽  
Vol 2071 (1) ◽  
pp. 012052
Author(s):  
N A Zulkiflli ◽  
M D Shahrulnizahani ◽  
X F Hor ◽  
F A Phang ◽  
M F Rahmat ◽  
...  
Keyword(s):  
Finite Element ◽  
Cultured Cells ◽  
Electrical Capacitance Tomography ◽  
Finite Element Models ◽  
Capacitive Sensing ◽  
Electrical Capacitance ◽  
Cross Sectional ◽  
Electrode Size ◽  
Cell Monitoring ◽  
Capacitance Tomography

Abstract Cell sensing and monitoring using capacitive sensors are widely used in cell monitoring because of the flexible and uncomplicated design and fabrication. Previous work from many different fields of applications has integrated capacitive sensing technique with tomography to produce cross-sectional images of the internal dielectric distribution. This paper carried an investigation on the capabilities of four 16-channel sensor electrodes with different electrode sizes to detect the change in the dielectric distribution of the cultured cells. All three 16-channel sensor electrodes are designed and simulate on COMSOL 6.3a Multiphysics. The pre-processing results obtained from three finite element models (FEM) of ECT sensor configurations in detecting the cell phantom shows that bigger electrodes size are more sensitive to permittivity distribution.

scholarly journals Design Method and Finite Element Analysis of a New Prefabricated Steel Special-shaped Lattice Column

2020 ◽  
Vol 198 ◽  
pp. 03012
Author(s):  
Zhenghui Qi ◽  
Xiaotong Peng ◽  
Jie Man ◽  
Chen Lin ◽  
Wenxu Duan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cross Section ◽  
Seismic Behavior ◽  
Design Method ◽  
Steel Structure ◽  
Hysteretic Behavior ◽  
Structural Performance ◽  
Finite Element Models ◽  
Element Analysis

A new steel special-shaped lattice column (SSLC) was proposed, which can be used in prefabricated steel structure residence. The finite element models of four SSLC with different cross-section (L-shaped, T1-shaped, T2-shaped and X-shaped) were established under cyclic loading by using ABAQUS, in which the strength, lateral resist capacity and hysteretic behavior were analyzed. The results indicate that SSLC has adequate strength, stiffness and safety redundancy. Among the four SSLC, the SSLC with X-shaped has the best structural performance and seismic behavior.

scholarly journals Spider Diagram for Tubular Expansion with Restraints

2013 ◽  
Vol 10 (1) ◽  
pp. 1
Author(s):  
F Marketz ◽  
SA Al-Hiddabi
Keyword(s):  
Finite Element ◽  
Statistical Analysis ◽  
Cross Section ◽  
Strong Correlation ◽  
Parametric Study ◽  
Element Model ◽  
Two Dimensional ◽  
Operational Parameters ◽  
Expansion Process ◽  
Borehole Data

 The aim of this study is to explain the mechanics of tubular expansion in irregularly shaped boreholes such as those frequently observed in the upper Natih reservoirs. Statistical analysis of borehole data does not indicate a strong correlation between the non-circularity and expanded tubular’s in such boreholes. A two-dimensional (2-D) finite element model was developed using commercial software to determine the non-circularity of an expanded tubular and those data were compared with the measured values. A parametric study was also conducted and spider plots were generated to determine the amount of irregularity in the expanded tubulars so that optimum operational parameters could be identified to limit cross-section irregularities during the expansion process. 

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