scholarly journals Enhanced Ultimate Shear Capacity of Concave Square Frustum-Shaped Wet Joint in Precast Steel–Concrete Composite Bridges

2021 ◽  
Vol 11 (4) ◽  
pp. 1915
Author(s):  
Fan Feng ◽  
Fanglin Huang ◽  
Weibin Wen ◽  
Peng Ge ◽  
Yong Tao
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
Concrete Strength ◽  
Shear Capacity ◽  
Fe Analysis ◽  
Fe Model ◽  
Shear Key ◽  
Model Based ◽  
Composite Bridges ◽  
Ultimate Shear Capacity

Wet joints are widely used in precast steel–concrete composite bridges to accelerate the construction of bridges, though a conventional wet joint usually has a poor ultimate shear capacity. To improve the shear capacity of the wet joint, a concave square frustum-shaped wet joint was proposed, and the failure modes and ultimate shear capacity were studied experimentally and numerically. Specimens with concave square frustum-shaped and conventional wet joints (labeled as S-SWJ and S-CWJ) were fabricated, and experiments were performed on them. The results showed that the ultimate shear capacity of S-SWJ was substantially enhanced compared to that of S-CWJ. To further explore the ultimate shear capacity of S-SWJ, the failure modes and the influences of concrete strength and shear key angle on the ultimate shear capacity were studied using a validated finite element (FE) model. Based on the FE analysis, the guidelines for obtaining a wet joint with desirable shear capacity are presented, which is useful for the design of wet joints with high ultimate shear capacity.

Use of Design-by-Analysis for Designing Shear Key Structure

2009 ◽  
Author(s):  
Tomohiro Naruse ◽  
Tetsuya Kuwano ◽  
Mitsuhiro Narita ◽  
Taiji Hashimoto ◽  
Haruo Miura
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Rotating Machinery ◽  
Fe Analysis ◽  
Contact Condition ◽  
Bolted Joints ◽  
Fe Model ◽  
Shear Key ◽  
Pressure Tests ◽  
Structure Configuration

In many vessels with container, such as those involving rotating machinery, barrel casings are closed with disc shaped end covers on both axial sides. The end covers are fixed to the barrel casing with bolted joints or retaining devices. A shear key structure is often applied to pressurized vessels as a retaining device, because it can endure higher pressure than bolted joints can. Stress distribution in the shear key and the casing depends on the contact condition between the shear key and the casing. Thus, it is difficult to design a shear key structure merely by using Design-by-Formula procedures. We designed the shear key structure according to Design-by-Analysis procedures based on finite element (FE) analysis. By taking the contact condition between shear key and casing into consideration in an FE model and carrying out elastic and inelastic analyses, we developed a new shear key structure configuration. We will confirm the validity of the new shear key structure by means of pressure tests that will be conducted in May of 2009.

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.

Fire and Post-Fire Performance of Space Grid Structures

2012 ◽  
Vol 238 ◽  
pp. 621-624 ◽  
Author(s):  
Guang Yong Wang ◽  
Xing Qiang Wang ◽  
Guang Wei Liu
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
Fe Model ◽  
Fire Damage ◽  
Fire Performance ◽  
Membrane Action ◽  
Load Bearing Capacity ◽  
Space Grid ◽  
Deformation Stress ◽  
In Fire

A fire performance finite element (FE) model of space grid structures in fire and after fire is proposed, and deformation, stress redistribution, failure modes of grid structures are also studied. The result shows that tensile membrane action arises when the grid is loaded after fire, and the load bearing capacity after fire is reduced by fire damage.

scholarly journals Combined Flexural and Shear Strengthening of RC T-Beams with FRP and TRM: Experimental Study and Parametric Finite Element Analyses

Buildings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 520
Author(s):  
Daniel A. Pohoryles ◽  
Jose Melo ◽  
Tiziana Rossetto
Keyword(s):  
Experimental Study ◽  
Finite Element ◽  
Shear Capacity ◽  
Fe Model ◽  
Rc Beams ◽  
Shear Strengthening ◽  
Flexural Strengthening ◽  
Existing Structures ◽  
The Difference ◽  
Reinforcement Design

Due to inadequacies of reinforcement design in older structures and changes in building codes, but also the change of building use in existing structures, reinforced concrete (RC) beams often require upgrading during building renovation. The combined shear and flexural strengthening with composite materials, fibre-reinforced polymer sheets (FRP) and textile reinforced mortars (TRM), is assessed in this study. An experimental campaign on twelve half-scale retrofitted RC beams is presented, looking at various parameters of interest, including the effect of the steel reinforcement ratio on the retrofit effectiveness, the amount of composite material used for strengthening and the effect of the shear span, as well as the difference in effectiveness of FRP and TRM in strengthening RC beams. Significant effects on the shear capacity of composite retrofitted beams are observed for all studied parameters. The experimental study is used as a basis for developing a detailed finite element (FE) model for RC beams strengthened with FRP. The results of the FE model are compared to the experimental results and used to design a parametric study to further study the effect of the investigated parameters on the retrofit effectiveness.

scholarly journals Numerical analysis of circular and square section concrete filled aluminum tubes under axial compression

2020 ◽  
Vol 14 (54) ◽  
pp. 169-181
Author(s):  
Pan Jinlong ◽  
Li Guanhua ◽  
Jingming Cai
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Axial Compression ◽  
Parametric Analysis ◽  
Concrete Strength ◽  
Fe Model ◽  
Fe Method ◽  
The Core ◽  
Aluminum Tubes ◽  
Core Concrete

In this paper, the finite element (FE) method was used to investigate the axial compressive behaviors of circular and square concrete filled aluminum tubes (CFAT). Firstly, the simulational results were compared with the experimental results and the accuracy of the proposed FE model was verified. On this basis, the FE model was further applied to compare the mechanical properties of both circular and square CFATs under axial compression. It was found that the circular CFATs have a better effect on restraining the core concrete than square CFATs. The parametric analysis was also conducted based on the proposed FE model. It was noticed that the mechanical differences of the two kinds of CFATs gradually decreased with the increase of the aluminum ratio, aluminum strength and concrete strength.

scholarly journals Identification of Surgical Plan for Syndesmotic Fixation Procedure Based on Finite Element Method

2020 ◽  
Vol 10 (12) ◽  
pp. 4349 ◽  
Author(s):  
Tae Sik Goh ◽  
Beop-Yong Lim ◽  
Jung Sub Lee ◽  
Chi-Seung Lee
Keyword(s):  
Finite Element ◽  
Simulation Method ◽  
Fe Analysis ◽  
Von Mises Stress ◽  
Fe Model ◽  
Syndesmotic Screw ◽  
Surgical Options ◽  
Biomechanical Parameters ◽  
Von Mises ◽  
Two Parameters

Syndesmosis injuries account for approximately 20% of ankle fractures that require surgery. Although multiple surgical options are available, all of them are based on metal screws. Serious complications that arise when applying metal screws include screw loosening or breakage. To prevent such complications, we applied a simulation method using a finite element (FE) analysis. We created a 3D FE model of an ankle joint and conducted an FE analysis focusing on syndesmosis in terms of the level, material, and diameter of the syndesmotic screw and the number of penetrated cortical bones. The magnitude and direction of the force applied to the tibia in the midstance state were considered for simulating the model. The maximum von-Mises stress and syndesmosis widening were analyzed in terms of different biomechanical parameters. We identified the characteristics of the most biomechanically stable syndesmotic screw and its fixation point on the basis of the two parameters. We demonstrated that the ideal syndesmotic screw fixation should be fixed at a level 20 to 25 mm above the ankle using a 4.5 mm titanium screw.

The Modeling Study on Kinematic Interface Joints Based on Accordant Displacement Method

2010 ◽  
Vol 29-32 ◽  
pp. 48-53
Author(s):  
Xue Qian Chen ◽  
Qiang Du ◽  
Xiao Juan Chen
Keyword(s):  
Finite Element ◽  
Solid State Laser ◽  
Fe Analysis ◽  
Ambient Vibration ◽  
Fe Model ◽  
Mean Square ◽  
Test Results ◽  
Contact Form ◽  
Displacement Method ◽  
Reflector System

The kinematic interface joints are widely used in reflector systems of the high-power solid-state laser facilities. In order to get better finite element(FE) analysis results of reflector systems, it is important to model the joints exactly. The accordant displacement method is used for modeling the joints according to the contact form of joints. The FE model of the reflector system is built subjected to the assuming, the modal analysis and the ambient vibration calculations are carried out. The computing results of inherent frequencies, measure points’ root mean square(RMS) displacements and the transfer characteristics of four kinematic interface positions are accordant with that of the test results. The compared results show that the method modeling the kinematic interface joints is feasible in the paper.

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.

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.

scholarly journals Feasibility Study on Tension Estimation Technique for Hanger Cables Using the FE Model-Based System Identification Method

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Kyu-Sik Park ◽  
Taek-Ryong Seong ◽  
Myung-Hyun Noh
Keyword(s):  
Finite Element ◽  
System Identification ◽  
Boundary Conditions ◽  
Natural Frequency ◽  
Inverse Analysis ◽  
Finite Element Models ◽  
Fe Model ◽  
Identification Methods ◽  
System Identification Method ◽  
Model Based

Hanger cables in suspension bridges are partly constrained by horizontal clamps. So, existing tension estimation methods based on a single cable model are prone to higher errors as the cable gets shorter, making it more sensitive to flexural rigidity. Therefore, inverse analysis and system identification methods based on finite element models are suggested recently. In this paper, the applicability of system identification methods is investigated using the hanger cables of Gwang-An bridge. The test results show that the inverse analysis and systemic identification methods based on finite element models are more reliable than the existing string theory and linear regression method for calculating the tension in terms of natural frequency errors. However, the estimation error of tension can be varied according to the accuracy of finite element model in model based methods. In particular, the boundary conditions affect the results more profoundly when the cable gets shorter. Therefore, it is important to identify the boundary conditions through experiment if it is possible. The FE model-based tension estimation method using system identification method can take various boundary conditions into account. Also, since it is not sensitive to the number of natural frequency inputs, the availability of this system is high.

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