scholarly journals PARAMETRIC STUDIES ON THE COMPONENT-BASED APPROACH TO MODELLING BEAM BOTTOM FLANGE BUCKLING AT ELEVATED TEMPERATURES

2016 ◽  
Vol 56 (2) ◽  
pp. 132
Author(s):  
Guan Quan ◽  
Shan-Shan Huang ◽  
Ian Burgess
Keyword(s):  
Finite Element ◽  
Analytical Model ◽  
Elevated Temperatures ◽  
Finite Element Models ◽  
Bottom Flange ◽  
Class 1 ◽  
Shear Buckling ◽  
Post Buckling ◽  
Parametric Studies ◽  
Better Than

<p>In this study, an analytical model of the combination of beam-web shear buckling and bottom-flange buckling at elevated temperatures has been introduced. This analytical model is able to track the force-deflection path during post-buckling. A range of 3D finite element models has been created using the ABAQUS software. Comparisons have been carried out between the proposed analytical model, finite element modelling and an existing theoretical model by Dharma (2007). Comparisons indicate that the proposed method is able to provide accurate predictions for Class 1 and Class 2 beams, and performs better than the existing Dharma model, especially for beams with high flange-to-web thickness ratios. A component-based model has been created on the basis of the analytical model, and will in due course be implemented in the software Vulcan for global structural fire analysis.</p>

scholarly journals A Component-based Approach to Modelling Beam Bottom Flange Buckling at Elevated Temperatures

2016 ◽  
Author(s):  
Guan Quan ◽  
Shan-Shan Huang ◽  
Ian Burgess
Keyword(s):  
Finite Element ◽  
Analytical Model ◽  
Elevated Temperatures ◽  
Finite Element Models ◽  
Bottom Flange ◽  
Class 1 ◽  
Slender Beams ◽  
Shear Buckling ◽  
Post Buckling ◽  
Better Than

In this study, an analytical model of the combination of beam-web shear buckling and bottom-flange buckling at elevated temperatures has been created. This analytical model is able to track the force-deflection path in the post-buckling stage. A range of 3D finite element models has been created using the ABAQUS software. Comparisons have been carried out between the proposed analytical model, finite element modelling and the existing Dharma’s theoretical model. Comparisons indicate that the proposed method is able to provide with accurate predictions for Class 1 and Class 2 beams, and performs better than the existing model, especially for slender beams. A component-based model has been created based on the analytical model, and in due course to be implemented into the software Vulcan for global structural fire analysis.

Study on the Effect of Ways of Gear Relief on Contact Force of Teeth Face

2011 ◽  
Vol 415-417 ◽  
pp. 66-70
Author(s):  
Yong Ma ◽  
Qi Huang ◽  
Tian Ji ◽  
Zhi Feng Lou
Keyword(s):  
Finite Element ◽  
Contact Force ◽  
Contact Analysis ◽  
Finite Element Models ◽  
Contact Method ◽  
Helical Gears ◽  
Profile Modification ◽  
Involute Gears ◽  
Main Basis ◽  
Better Than

An accurate finite element contact analysis of helical gears was done directly under ANSYS, while the integrated elastic deformation of the meshed teeth was extracted directly from the finite element contact analysis results, and considered as the main basis of the amount of tooth profile modification. Linear, conic, cubic, and sine relief curve are compiled and established in MATLAB, on which gear models of two ways of modified gear are built. Under the same modified parameters, contact method is used on the proposed finite element models of gears by software LS-DYNA, and the effect of the two ways of gear relief on contact force on teeth face is analyzed. The results show that the effect of a pair of gears relief is better than one gear relief for linear and conic relief curve, and the effect of one gear relief is better than a pair of gears relief for cubic and sine relief curve. So dynamic simulation on modified involute gears has great significance for reducing contact force of teeth face of gears.

A Combined Analytical and Numerical Approach to Analyze Mud Motor Excited Vibrations in Drilling Systems

2015 ◽  
Author(s):  
Andreas Hohl ◽  
Carsten Hohl ◽  
Christian Herbig
Keyword(s):  
Finite Element ◽  
Analytical Model ◽  
Field Measurements ◽  
Element Model ◽  
Numerical Approach ◽  
Analytical Models ◽  
Finite Element Models ◽  
Beam Model ◽  
Direct Influence ◽  
Practical Applications

Severe vibrations in drillstrings and bottomhole assemblies can be caused by cutting forces at the bit or mass imbalances in downhole tools. One of the largest imbalances is related to the working principle of the so-called mud motor, which is an assembly of a rotor that is maintained by the stator. One of the design-related problems is how to minimize vibrations excited by the mud motor. Simulation tools using specialized finite element methods (FEM) are established to model the mechanical behavior of the structure. Although finite element models are useful for estimating rotor dynamic behavior and dynamic stresses of entire drilling systems they do not give direct insight how parameters affect amplitudes and stresses. Analytical models show the direct influence of parameters and give qualitative solutions of design related decisions. However these models do not provide quantitative numbers for complicated geometries. An analytical beam model of the mud motor is derived to calculate the vibrational amplitudes and capture basic dynamic effects. The model shows the direct influence of parameters of the mud motor related to the geometry, material properties and fluid properties. The analytical model is compared to the corresponding finite element model. Vibrational amplitudes are discussed for different modes and parameter changes. Finite element models of the entire drilling system are used to verify the findings from the analytical model using practical applications. The results are compared to time domain and statistical data from laboratory and field measurements.

Seismic behavior of exteriorbeam–column joints with high-performance steel rebar: Experimental and numerical investigations

2020 ◽  
Vol 24 (1) ◽  
pp. 90-106
Author(s):  
Fei Gao ◽  
Zhiqiang Tang ◽  
Shilong Mei ◽  
Biao Hu ◽  
Shitao Huang ◽  
...  
Keyword(s):  
Finite Element ◽  
Axial Load ◽  
High Performance ◽  
Compressive Loading ◽  
Load Ratio ◽  
Reinforcement Ratio ◽  
Finite Element Models ◽  
Flexural Failure ◽  
Axial Load Ratio ◽  
Parametric Studies

Three full-scale exterior beam–column joints with anti-seismic steel reinforcement were tested under quasi-static cyclic loading and column axial compressive loading. The test variables were column axial load ratio and joint core hoop reinforcement ratio. Experimental results, including failure mode, hysteretic curve, ductility, energy dissipation, stiffness degradation, and decoupling of deformations, were presented and analyzed. The tests revealed that the anti-seismic rebar resulted in good joint seismic performance and that column axial load ratio and joint core hoop reinforcement ratio impose limited influence of joint performance when the joint failed in beam flexural failure. The calibrated finite element models developed based on OpenSees were then used to simulate the behavior of joint specimens. Parametric studies via finite element modeling were performed to study the influence of various parameters on the performance of beam–column joints.

scholarly journals How does tooth cusp radius of curvature affect brittle food item processing?

2013 ◽  
Vol 10 (84) ◽  
pp. 20130240 ◽  
Author(s):  
Michael A. Berthaume ◽  
Elizabeth R. Dumont ◽  
Laurie R. Godfrey ◽  
Ian R. Grosse
Keyword(s):  
Finite Element ◽  
Food Item ◽  
Sampling Method ◽  
High Stress ◽  
Radius Of Curvature ◽  
Finite Element Models ◽  
Partial Support ◽  
Stress Concentrations ◽  
Food Items ◽  
Better Than

Tooth cusp sharpness, measured by radius of curvature (RoC), has been predicted to play a significant role in brittle/hard food item fracture. Here, we set out to test three existing hypotheses about this relationship: namely, the Blunt and Strong Cusp hypotheses, which predict that dull cusps will be most efficient at brittle food item fracture, and the Pointed Cusp hypothesis, which predicts that sharp cusps will be most efficient at brittle food item fracture using a four cusp bunodont molar. We also put forth and test the newly constructed Complex Cusp hypothesis, which predicts that a mixture of dull and sharp cusps will be most efficient at brittle food item fracture. We tested the four hypotheses using finite-element models of four cusped, bunodont molars. When testing the three existing hypotheses, we assumed all cusps had the same level of sharpness (RoC), and gained partial support for the Blunt Cusp hypotheses. We found no support for the Pointed Cusp or Strong Cusp hypotheses. We used the Taguchi sampling method to test the Complex Cusps hypothesis with a morphospace created by independently varying the radii of curvature of the four cusps in the buccolingual and mesiodistal directions. The optimal occlusal morphology for fracturing brittle food items consists of a combination of sharp and dull cusps, which creates high stress concentrations in the food item while stabilizing the food item and keeping the stress concentrations in the enamel low. This model performed better than the Blunt Cusp hypothesis, suggesting a role for optimality in the evolution of cusp form.

An integrated experimental and finite element approach for wrinkling limit prediction of Inconel 718 alloy at elevated temperatures

2021 ◽  
pp. 030932472110430
Author(s):  
Gauri Mahalle ◽  
Nitin Kotkunde ◽  
Amit Kumar Gupta ◽  
Swadesh Kumar Singh
Keyword(s):  
Finite Element ◽  
Elevated Temperature ◽  
Inconel 718 ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Functional Requirements ◽  
Inconel 718 Alloy ◽  
Different Temperatures ◽  
Post Buckling ◽  
Element Approach

Wrinkling is generally induced because of metal instability and considered as an undesirable defect in sheet metal forming processes. Wrinkling leads to severe influence on functional requirements and aesthetic appeal of final component. Thus, the present research is mainly dedicated on the experimental and numerical analysis for wrinkling behavior prediction of Inconel 718 alloy at elevated temperature conditions. Initially, Yoshida buckling tests (YBT) have been conducted to investigate wrinkling tendencies of Inconel 718 alloy from room temperature (RT) to 600°C by an interval of 200°C. Subsequently, Finite Element (FE) analysis of YBT has been performed to analyze post buckling behavior. Critical strain values at onset of wrinkling are determined and strain based wrinkling limit curves (ε-WLCs) are plotted at different temperatures. In-plane principal strains are transferred to effective plastic strain (EPS) versus triaxiality (η) space to differentiate the transformation between safe and wrinkling instability. Finally, complete forming behavior of alloy is represented by means of fracture, forming, and wrinkling limit curves. The gap between forming and wrinkling limit curves at elevated temperature is ∼1.5 times higher than that at room temperature.

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