Experimental and Numerical Study on Crashworthiness Parameters of Mild Steel Square Tube under Quasi-Static Axial Compression

2020 ◽  
Vol 12 (2) ◽  
Author(s):  
Shinde Rushikesh ◽  
Mali Kiran ◽  
M. Kathiresan ◽  
Kulkarni Dhananjay
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Experimental Testing ◽  
Testing Machine ◽  
Fe Analysis ◽  
Fe Model ◽  
Element Analysis ◽  
Static Test ◽  
Collapse Mode ◽  
Crash Behaviour

In the present research, an experimental and numerical study on the crush response of square tube is presented. The explicit Finite Element Analysis (FEA) in LS-DYNA software is carried out to simulate crash behaviour under the quasi-static test conditions. Compression load is applied quasi-statically in an experimental study on the square tube specimens using Universal Testing Machine (UTM). In quasi-static test the bottom platen speed used is 1 mm/min. From experimental testing symmetric collapse mode is observed in all deformed specimens. The development of the symmetric collapse mode in a Finite Element (FE) model is also observed. Thus fold formation and crush response predicted by FE analysis are observed to be in very good correlation with the results obtained from experimental testing. Furthermore, the effect of the thickness of tube on crashworthiness parameters is investigated. From the FE analysis, it is found that the thickness of the square tube influences significantly the crashworthiness parameters.

scholarly journals Design and analysis of concrete-filled tubular flange girders under combined loading

2021 ◽  
pp. 136943322110015
Author(s):  
Rana Al-Dujele ◽  
Katherine Ann Cashell
Keyword(s):  
Finite Element ◽  
Axial Force ◽  
Failure Modes ◽  
Numerical Study ◽  
Combined Loading ◽  
Torsional Stiffness ◽  
Fe Model ◽  
Combined Effects ◽  
Element Analysis ◽  
Hollow Section

This paper is concerned with the behaviour of concrete-filled tubular flange girders (CFTFGs) under the combination of bending and tensile axial force. CFTFG is a relatively new structural solution comprising a steel beam in which the compression flange plate is replaced with a concrete-filled hollow section to create an efficient and effective load-carrying solution. These members have very high torsional stiffness and lateral torsional buckling strength in comparison with conventional steel I-girders of similar depth, width and steel weight and are there-fore capable of carrying very heavy loads over long spans. Current design codes do not explicitly include guidance for the design of these members, which are asymmetric in nature under the combined effects of tension and bending. The current paper presents a numerical study into the behaviour of CFTFGs under the combined effects of positive bending and axial tension. The study includes different loading combinations and the associated failure modes are identified and discussed. To facilitate this study, a finite element (FE) model is developed using the ABAQUS software which is capable of capturing both the geometric and material nonlinearities of the behaviour. Based on the results of finite element analysis, the moment–axial force interaction relationship is presented and a simplified equation is proposed for the design of CFTFGs under combined bending and tensile axial force.

Overpressure Fragility Evaluation of a Mark I Drywell Using Thermal-Mechanical Finite Element Analysis

2014 ◽  
Author(s):  
Mohamed M. Talaat ◽  
David K. Nakaki ◽  
Kyle S. Douglas ◽  
Philip S. Hashimoto ◽  
Yahya Y. Bayraktarli
Keyword(s):  
Finite Element ◽  
Stress Analysis ◽  
Fe Analysis ◽  
Heat Transfer Analysis ◽  
Fe Model ◽  
Head Region ◽  
Element Analysis ◽  
Differential Movement ◽  
Steady State Heat ◽  
Steady State Heat Transfer

The overpressure fragility of a Mark I boiling water reactor drywell was performed by detailed finite element (FE) analysis. The drywell overpressure capacity is controlled by the onset of leakage in the bolted head flange connection once separation exceeds the capacity of the silicone rubber O-ring seals. The FE analysis was conducted at 6 discrete accident temperatures, ranging from 150 to 425°C. The overpressure evaluation used an axisymmetric model of the drywell head region for computational efficiency, and verified it by comparing to results from one FE model which used 3D solid elements. The mechanical properties of the steel materials were defined as temperature-dependent linear-elastic. The median overpressure capacity at each temperature was determined using a 2-step thermal-stress analysis procedure. First, a steady-state heat transfer analysis was conducted to map out the temperature distribution in the drywell wall, which is exposed to the accident temperature on the inside and ambient temperature on the outside. Second, a quasi-static multi-step stress analysis was performed. The vertical differential movement between the flange surfaces was monitored and compared to the O-ring rebound capacity to define the pressure at the onset of leakage. After leakage occurred, the relationship between leakage area and increased pressure was recorded. The evaluation predicted the median overpressure capacity and the lognormal standard deviation for uncertainty in O-ring rebound capacities, bolt preload, and model sophistication, in addition to the median pressure-leak area relationship.

The biomechanical study of cervical spine: A Finite Element Analysis

2021 ◽  
pp. 039139882199549
Author(s):  
Pechimuthu Susai Manickam ◽  
Sandipan Roy
Keyword(s):  
Finite Element ◽  
Cervical Spine ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Biomechanical Study ◽  
Fe Analysis ◽  
Von Mises Stress ◽  
Fe Model ◽  
Element Analysis ◽  
End Plate

The biomechanical study helps us to understand the mechanics of the human cervical spine. A three dimensional Finite Element (FE) model for C3 to C6 level was developed using computed tomography (CT) scan data to study the mechanical behaviour of the cervical spine. A moment of 1 Nm was applied at the top of C3 vertebral end plate and all degrees of freedom of bottom end plate of C6 were constrained. The physiological motion of the cervical spine was validated using published experimental and FE analysis results. The von Mises stress distribution across the intervertebral disc was calculated along with range of motion. It was observed that the predicted results of functional spine units using FE analysis replicate the real behaviour of the cervical spine.

scholarly journals Modeling and Comparative Analysis of Different Generic Cross Section B-Pillar Design in Roof Crush Impact

2021 ◽  
pp. 187-200
Author(s):  
Pankaj Kumar Jha ◽  
Rachayya Arakerimath
Keyword(s):  
Finite Element ◽  
Energy Absorption ◽  
Cross Section ◽  
Cross Sections ◽  
High Energy ◽  
Fe Model ◽  
Performance Study ◽  
Element Analysis ◽  
Pillar Design ◽  
Static Test

When a vehicle tips over onto its roof or side due to internal or external force on a vehicle is called Rollover impact. Rollover is a very critical impact compared to another mode of vehicle impacts. B-pillar and its cross-section design are very critical in the rollover impacts by reducing the cabin intrusion of vehicle. B-pillar absorbs most of the energy at the time of rollover and reduces the fatality rate of the passenger. In this work, a B-pillar finite element (FE) model is modeled to analyze as per FMVSS216a standard protocol to check the critical performance. Two generic cross-sections of the B-pillar are considered for preliminary assessment. This B-pillar designs FE model (cut model) are modeled and analyzed for FMVSS216a using LS-DYNA explicit code. The FMVS216a lab test is a quasi-static test and LS-DYNA is the well-accepted FEA tool to simulate the quasi-static test. LS-DYNA software is widely accepted as a multi-purpose finite element analysis (FEA), capable of solving complex problems in the field of Automobile, Aerospace, etc. So LS-DYNA is considered for the study of the B-Pillar simulations. Both the B-pillar designs are accessed and compared with respect to energy absorption, crush resistance characteristics with respect to the full vehicle rollover test. With the detailed performance study of both cross-section designs under rollover impact, the best performing B-pillar design in terms of high energy absorption and high vehicle resistance is selected for furtheroptimization study to meet the Roof crush standard requirements.

Visco-Anisotropic Hyperelastic Finite Element Analysis of Knee Joint Considering Deformation Induced Anisotropy Evolution of Meniscus

2017 ◽  
Author(s):  
Tsuyoshi Eguchi ◽  
Yoshihiro Tomita ◽  
Koji Yamamoto ◽  
Yusuke Morita ◽  
Eiji Nakamachi
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Knee Joint ◽  
Constitutive Equations ◽  
Collagen Fiber ◽  
Collagen Fibers ◽  
Fe Analysis ◽  
Fe Model ◽  
Element Analysis ◽  
Human Knee Joint

Recently, the observation technology of micro structure has made great progress, and then collagen fiber orientation of meniscus can be measured accurately. This makes it possible to evaluate the stress in knee joint by considering the collagen fiber orientations at the micro scale. In this study, we developed visco-isotropic/anisotropic hyperelastic constitutive equations (Iso-VHE/Aniso-VHE) for menisci, which can reflect the initial collagen fiber orientations and their deformation induced rotations. Subsequently, we constructed a finite element (FE) model of normal human knee joint by using the magnetic resonance (MR) tomography images. The FE analysis with the proposed constitutive equations and FE model clarifies the reinforcement effect of collagen fibers on mechanical characteristics of knee joint. Our computational prediction clarified that the stress concentration occurred on the contact parts of articular cartilages of femur and tibia, which met the tendency of the experimental results. Furthermore, the maximum compressive stresses evaluated by Aniso-VHE always showed a lower value as compared with Iso-VHE. This suggested that the anisotropy of meniscal collagen fibers relieved the stress concentration and lowered the maximum value. Therefore, our proposed FE analysis was proved to have a potential to reveal the functions of meniscus and knee joint.

Finite element analysis of tension-loaded ASTM A325 bolts under simulated fire loading

2018 ◽  
Vol 9 (1) ◽  
pp. 2-18
Author(s):  
Ali Shrih ◽  
Adeeb Rahman ◽  
Mustafa Mahamid
Keyword(s):  
Finite Element ◽  
Experimental Testing ◽  
Three Dimensional ◽  
Steel Structures ◽  
Fe Model ◽  
Repeated Testing ◽  
Element Analysis ◽  
Content Type ◽  
Fire Loading ◽  
Simulated Fire

Purpose Nuts and bolts have been used as fasteners of steel structures for many years. However, these structures remain susceptible to fire damage. While conducting fire experiments on steel structures is sometimes necessary, to better understand their behavior, such experiments remain costly and require specialized equipment and testing facilities. This paper aims to present a highly accurate three-dimensional (3D) finite element (FE) model of ASTM A325 bolt subjected to tension loading under simulated fire conditions. The FE model is compared to the results of experimental testing for verification purposes and is proven to predict the response of similar bolts up to certain temperatures without the need for repeated testing. Design/methodology/approach A parametric 3D FE model simulating tested specimens was constructed in the ANSYS Workbench environment. The model included the intricate details of the bolt and nut threads, as well as all the other components of the specimens. A pretension load, a tension force and a heat profile were applied to the model, and a nonlinear analysis was performed to simulate the experiments. Findings The results of the FE model were in good agreement with the experimental results, deviations of results between experimental and FE results were within acceptable range. This should allow studying the behavior of structural bolts without the need for expensive testing. Originality/value Detailed 3D FE models have been created by the authors have been created to study the behavior of structural bolts and compared with experiments conducted by the authors.

Finite Element Analysis on Load-Bearing Behavior of Concrete Filled Steel Tubular Composite Frames

2011 ◽  
Vol 71-78 ◽  
pp. 1683-1686
Author(s):  
Yuan Huang ◽  
Wei Jian Yi ◽  
Jian Guo Nie
Keyword(s):  
Finite Element ◽  
Seismic Behavior ◽  
Fe Analysis ◽  
Constitutive Law ◽  
Plastic Behavior ◽  
Fe Model ◽  
Element Analysis ◽  
Composite Frames ◽  
Composite Frame ◽  
Analysis Models

This paper presents a nonlinear finite element (FE) analysis on the mechanic behavior of concrete filled steel tubular (CFST) composite frames. The main purpose of the FE analysis was to investigate the seismic behavior of composite frames. Three kinds of nonlinearity, namely material nonlinearity, contact nonlinearity and geometry nonlinearity, were taken into account in the FE model using MSC.Marc. The element type, connection between element, material constitutive law and boundary condition was described in detail. The elasto-plastic behavior, as well as fracture and post-fracture behavior, of the FE analysis models fitted well with those of the test specimens. The beam and panel zone deformation of the analysis models is also in good agreement with that of the test specimen. It is concluded that FE model of CFST composite frame is reliable and could be regarded as a helpful tool to expand the information on seismic behavior of CFST composite frame.

A Study on the Effect of Non-Idealized Crack on a 90° Elbow by Using Finite Element Analysis

2018 ◽  
Author(s):  
Jae-Hee Kim ◽  
Min-Kyu Kim ◽  
Ye-Rin Choi ◽  
Doo-Ho Cho ◽  
Moon Ki Kim ◽  
...  
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Limit Load ◽  
Element Model ◽  
Assessment Method ◽  
Accurate Solution ◽  
Fe Model ◽  
Plastic Limit ◽  
Element Analysis ◽  
Plastic Limit Load

The present paper proposed the modified limit load solution related to code case N-513-4 which is currently actively researched. To apply to assessment method for an elbow in code case N-513-4, the crack should be postulated as the idealized circumferential through-wall crack (TWC). For this reason, it could be led to overestimate the results due to the assumption of real crack shape. Then, the many research which is related to an accurate solution for a straight pipe by considering realistic crack has been investigated. However, the accurate solution for the elbow with non-idealized TWC is still lacked. Therefore, based on three-dimensional finite element model, the effect of non-idealized circumferential TWC on plastic limit load was investigated under internal pressure. To do this, the finite element (FE) model and analysis procedure employed in the present numerical study were validated by comparing the present finite element analyses result with existing solutions for idealized TWC in the elbow. Then, the correction factor for calculating plastic limit load was newly proposed as a tabulated form by considering practical ranges of geometry.

A Local-to-Global Dimensional Error Calculation Framework for the Riveted Assembly Using Finite-Element Analysis

2015 ◽  
Vol 138 (3) ◽  
Author(s):  
Jun Ni ◽  
Wencheng Tang ◽  
Yan Xing ◽  
Kecun Ben ◽  
Ming Li
Keyword(s):  
Finite Element ◽  
Large Scale ◽  
Fe Analysis ◽  
Main Process ◽  
Fe Model ◽  
Parameter Uncertainties ◽  
Element Analysis ◽  
Dimensional Error ◽  
Error Calculation ◽  
Inherent Strain

Mechanical structures of large-scale antennas are sheet metals connected by thousands of rivets. The antenna dimensional error after riveting often violates the limit allowed. The prediction of the global dimensional error induced by many rivet connections requires a rapid and accurate assembly deformation calculation method. Main process parameters of these local rivet connections are the local connection dimension, material property, local clamp position, rivet upsetting direction, and the hammer time-to-displacement impact, except for the riveting sequence. We neglect the process parameter uncertainties and consider that the main riveting parameters equate to a dynamic finite-element (FE) model of single rivet connection. The dynamic FE analysis result yields an inherent strain database for the riveted local parts. Then, we propose an iterative loop of static FE analyses for the global structure taking the inherent strain database and possible former static FE analysis result as the boundary conditions. The loop forms a local-to-global framework. Two examples are involved through the framework representation and realistic application. Framework advantages include: (1) a good balance between the cost and precision of dimensional error calculation; (2) the sequence simulation of all the riveting operations; and (3) supporting the further assembly process optimization to reduce the global dimensional error of the assembly with thousands of rivets.

TO STUDY THE EFFECTS OF INTRASTROMAL CORNEAL RING GEOMETRY AND SURGICAL CONDITIONS ON THE POSTSURGICAL OUTCOMES THROUGH FINITE ELEMENT ANALYSIS

2016 ◽  
Vol 16 (07) ◽  
pp. 1650101 ◽  
Author(s):  
SALMAN N. KHAN ◽  
PANOS S. SHIAKOLAS
Keyword(s):  
Finite Element ◽  
Linear Regression Analysis ◽  
Fe Analysis ◽  
Fe Model ◽  
Control Parameters ◽  
Element Analysis ◽  
Intrastromal Corneal Ring ◽  
Implantation Depth ◽  
Depth Analysis ◽  
Surgical Conditions

Intrastromal corneal ring (ICR) is a transparent circular implant inserted in the cornea to provide structural support in an attempt to alleviate preexisting refractive errors. This is a surgical procedure whose success depends on control parameters such as, ICR geometry which includes ICR thickness and diameter, and surgical conditions which includes ICR implantation depth and diameter of corneal pocket. This research utilizes finite element (FE) analysis techniques to develop a high fidelity and computationally efficient three-dimensional axisymmetric cornea model to study the relative effects of ICR implant geometry and surgical conditions on the postsurgical shape of the cornea utilizing corneal apical displacement results. The FE analysis results indicate that ICR implantation reduces myopia, and the amount of myopic rectification is dependent on the control parameters which include ICR geometry and surgical conditions. The results show that an increase in ICR thickness leads to an increase in myopic rectification, whereas an increase in ICR radius leads to a decrease in myopic rectification. ICR implantation depth analysis results suggest that corneal depth of 40–75% provides steady myopic rectification. Corneal pocket diameter analysis revealed that smaller corneal pockets lead to increase in myopic rectification. Overall, the FE model results are in qualitative agreement with published clinical studies. Finally, the combined impact of the control parameters on myopic rectification was studied by conducting a sensitivity analysis and an equation relating myopic rectification with control parameters was developed utilizing simple linear regression analysis.

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