scholarly journals Structural safety and fatigue reliability assessments of a metro-train bolster

2019 ◽  
Vol 11 (1) ◽  
pp. 168781401882175 ◽  
Author(s):  
Jiexin Hu ◽  
Liyang Xie ◽  
Weiguang Sun ◽  
Xinkang Li ◽  
Xiao Lv ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Test Method ◽  
Structural Safety ◽  
Atmospheric Conditions ◽  
Fatigue Reliability ◽  
Static Test ◽  
Weak Points ◽  
Reliability Assessments

This article presents an economical and efficient way to assess the structural safety and fatigue reliability of the bolster, a key structure for the metro-train. First, its finite element model was validated based on the comparison between numerical results and experimental data of stresses and displacements recorded during a static test. Then, the fatigue life of the bolster under loading scheme was predicted using Gerber diagram, in which the validated finite element model was applied to determine the weak points, and its structural safety was also evaluated by a full-scale fatigue test and non-destructive test method. Finally, the metro-train bolster was modeled as a series system of weak points, and a new fatigue reliability model for mechanical component derived based on stress-life interference model was used to assess its fatigue reliability under the application of the design passenger number spectra. The results show that not only does this bolster satisfy the structural safety requirement during its service life, but also its fatigue reliability is more than 99.993% after 30-year service under normal atmospheric conditions.

Research on seismic behavior of special-shaped CFST column to H-section steel beam joint

2021 ◽  
pp. 136943322110073
Author(s):  
Yu Cheng ◽  
Yuanlong Yang ◽  
Binyang Li ◽  
Jiepeng Liu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Seismic Behavior ◽  
Failure Modes ◽  
Joint Stiffness ◽  
Load Ratio ◽  
Element Model ◽  
Steel Tube ◽  
Steel Beam ◽  
Static Test

To investigate the seismic behavior of joint between special-shaped concrete-filled steel tubular (CFST) column and H-section steel beam, a pseudo-static test was carried out on five specimens with scale ratio of 1:2. The investigated factors include stiffening types of steel tube (multi-cell and tensile bar) and connection types (exterior diaphragm and vertical rib). The failure modes, hysteresis curves, skeleton curves, stress distribution, and joint shear deformation of specimens were analyzed to investigate the seismic behaviors of joints. The test results showed the connections of exterior diaphragm and vertical rib have good seismic behavior and can be identified as rigid joint in the frames with bracing system according to Eurocode 3. The joint of special-shaped column with tensile bars have better seismic performance by using through vertical rib connection. Furthermore, a finite element model was established and a parametric analysis with the finite element model was conducted to investigate the influences of following parameters on the joint stiffness: width-to-thickness ratio of column steel tube, beam-to-column linear stiffness ratio, vertical rib dimensions, and axial load ratio of column. Lastly, preliminary design suggestions were proposed.

scholarly journals AEROTAXI ground static test and finite element model validation

2011 ◽  
Vol 3 (2) ◽  
pp. 57-64
Author(s):  
LOZICI-BRÎNZEI Dorin ◽  
◽  
TǍTARU Simion ◽  
BÎSCĂ Radu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Model Validation ◽  
Element Model ◽  
Static Test

scholarly journals Vibration-based Bayesian model updating of civil engineering structures applying Gaussian process metamodel

2019 ◽  
Vol 22 (16) ◽  
pp. 3487-3502
Author(s):  
Hossein Moravej ◽  
Tommy HT Chan ◽  
Khac-Duy Nguyen ◽  
Andre Jesus
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Bayesian Approach ◽  
Model Updating ◽  
Numerical Models ◽  
Element Model ◽  
The Body ◽  
Structural Safety ◽  
Discrepancy Function ◽  
The Finite Element Model

Structural health monitoring plays a significant role in providing information regarding the performance of structures throughout their life spans. However, information that is directly extracted from monitored data is usually susceptible to uncertainties and not reliable enough to be used for structural investigations. Finite element model updating is an accredited framework that reliably identifies structural behavior. Recently, the modular Bayesian approach has emerged as a probabilistic technique in calibrating the finite element model of structures and comprehensively addressing uncertainties. However, few studies have investigated its performance on real structures. In this article, modular Bayesian approach is applied to calibrate the finite element model of a lab-scaled concrete box girder bridge. This study is the first to use the modular Bayesian approach to update the initial finite element model of a real structure for two states—undamaged and damaged conditions—in which the damaged state represents changes in structural parameters as a result of aging or overloading. The application of the modular Bayesian approach in the two states provides an opportunity to examine the performance of the approach with observed evidence. A discrepancy function is used to identify the deviation between the outputs of the experimental and numerical models. To alleviate computational burden, the numerical model and the model discrepancy function are replaced by Gaussian processes. Results indicate a significant reduction in the stiffness of concrete in the damaged state, which is identical to cracks observed on the body of the structure. The discrepancy function reaches satisfying ranges in both states, which implies that the properties of the structure are predicted accurately. Consequently, the proposed methodology contributes to a more reliable judgment about structural safety.

Design and Fatigue Life Analysis of a Motorcycle Frame

2014 ◽  
Author(s):  
Massimiliano Gobbi ◽  
Giorgio Previati ◽  
Giampiero Mastinu
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Finite Element Model ◽  
Experimental Tests ◽  
Element Model ◽  
Fe Model ◽  
Static Test ◽  
Weld Toe ◽  
Fatigue Life Analysis ◽  
Motorcycle Frame

An off-road motorcycle frame has been analyzed and modified to optimize its fatigue life. The fatigue life of the frame is very important to define the service life of the motorcycle. The strain levels on key parts of the frame were collected during experimental tests. It has been possible to locate the areas where the maximum stress level is reached. A finite element (FE) model of the frame has been developed and used for estimating its fatigue life. Static test bench results have been used to validate the FE model. The accuracy of the finite element model is good, the errors are always below 5% with respect to measured data. The mission profile of the motorcycle is dominated by off-road use, with stress levels close to yield point, so a strain-life approach has been applied for estimating the fatigue life of the frame. Particular attention has been paid to the analysis of the welded connections. A shell and a 3D FE model have been combined to simulate the stress histories at the welds. Two reference maneuvers have been considered as loading conditions. The computed stresses have been used to assess the life of the frame according to the notch stress approach (Radaj & Seeger). The method correlates the stress range in a idealized notch, characterized by a fictitious radius in the weld toe or root, to the fatigue life by using a single S-N curve. New technical frame layouts have been proposed and verified by means of the developed finite element model. The considered approach allows to speed up the design process and to reduce the testing phase.

scholarly journals Structural Safety Analysis Based on Seismic Service Conditions for Butterfly Valves in a Nuclear Power Plant

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Sang-Uk Han ◽  
Dae-Gyun Ahn ◽  
Myeong-Gon Lee ◽  
Kwon-Hee Lee ◽  
Seung-Ho Han
Keyword(s):  
Finite Element ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Finite Element Model ◽  
Nuclear Power ◽  
Dynamic Properties ◽  
Element Model ◽  
Structural Safety ◽  
Butterfly Valve ◽  
Design Response Spectrum

The structural integrity of valves that are used to control cooling waters in the primary coolant loop that prevents boiling within the reactor in a nuclear power plant must be capable of withstanding earthquakes or other dangerous situations. In this study, numerical analyses using a finite element method, that is, static and dynamic analyses according to the rigid or flexible characteristics of the dynamic properties of a 200A butterfly valve, were performed according to the KEPIC MFA. An experimental vibration test was also carried out in order to verify the results from the modal analysis, in which a validated finite element model was obtained via a model-updating method that considers changes in thein situexperimental data. By using a validated finite element model, the equivalent static load under SSE conditions stipulated by the KEPIC MFA gave a stress of 135 MPa that occurred at the connections of the stem and body. A larger stress of 183 MPa was induced when we used a CQC method with a design response spectrum that uses 2% damping ratio. These values were lower than the allowable strength of the materials used for manufacturing the butterfly valve, and, therefore, its structural safety met the KEPIC MFA requirements.

Model Test Research on the Pile Stress by Pseudo-Static Test of Pier-Foundation-Structure System

2011 ◽  
Vol 383-390 ◽  
pp. 6641-6645
Author(s):  
Ming Bo Ding ◽  
Xing Chong Chen
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Model Test ◽  
Element Model ◽  
Static Test ◽  
Structure System ◽  
Foundation Structure ◽  
Depth Curve

This paper mostly studied on the pile stress in the loess foundation when the pile and the soil are interacting by pseudo-static test of piers and piles in the remolded loess foundation indoor. We get the stress-depth curve of pile body. We get its finite element model by ANASYS and analyze the change of pile body stress.

Study on Detection Method of Bridge Structure Based on Quasi-Static Test

2014 ◽  
Vol 501-504 ◽  
pp. 1148-1151
Author(s):  
Chun Heng Feng ◽  
Yan Gao ◽  
Xi Sha Jin ◽  
Xing Na Shi
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Load ◽  
Static Load ◽  
Element Model ◽  
Load Test ◽  
Bridge Structure ◽  
Static Load Test ◽  
Static Test ◽  
Dynamic Load Test

Currently the bridge structure detections are mainly based on static load test and dynamic load test. The static load test has shortcomings of less test data, long time-consumption and high cost. However, the dynamic load test has the advantages of quick and convenient, its related technologies and theories are still not mature enough. To solve this problem, the detection of bridge structure based on quasi-static test is proposed in this paper. Quasi-static load is applied on the structure by moving the standard load vehicle slowly. Then create the structural finite element model and modify the model according to the measured data to make it consistent with the actual structure. The bridge actual structural mechanical properties can be acquired by conducting load test on the optimized structural finite element model. By doing this, the bridge safety could be evaluated quickly.

scholarly journals Effect of Long-Term Soil Deformations on RC Structures Including Soil-Structure Interaction

2020 ◽  
Vol 6 (12) ◽  
pp. 2290-2311
Author(s):  
Kamel Bezih ◽  
Alaa Chateauneuf ◽  
Rafik Demagh
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Soil Structure ◽  
Element Model ◽  
Soil Structure Interaction ◽  
Structural Safety ◽  
Soil Behavior ◽  
Rc Structures ◽  
Structure Interaction

Lifetime service of Reinforced Concrete (RC) structures is of major interest. It depends on the action of the superstructure and the response of soil contact at the same time. Therefore, it is necessary to consider the soil-structure interaction in the safety analysis of the RC structures to ensure reliable and economical design. In this paper, a finite element model of soil-structure interaction is developed. This model addresses the effect of long-term soil deformations on the structural safety of RC structures. It is also applied to real RC structures where soil-structure interaction is considered in the function of time. The modeling of the mechanical analysis of the soil-structure system is implemented as a one-dimensional model of a spring element to simulate a real case of RC continuous beams. The finite element method is used in this model to address the nonlinear time behavior of the soil and to calculate the consolidation settlement at the support-sections and the bending moment of RC structures girders. Numerical simulation tests with different loading services were performed on three types of soft soils with several compressibility parameters. This is done for homogeneous and heterogeneous soils. The finite element model of soil-structure interaction provides a practical approach to show and to quantify; (1) the importance of the variability of the compressibility parameters, and (2) the heterogeneity soil behavior in the safety RC structures assessment. It also shows a significant impact of soil-structure interaction, especially with nonlinear soil behavior versus the time on the design rules of redundant RC structures. Doi: 10.28991/cej-2020-03091618 Full Text: PDF

Structural Analysis of Universal Shaft Based on ANSYS

2011 ◽  
Vol 215 ◽  
pp. 244-248
Author(s):  
Fu Qiang Ying ◽  
Ling Dong Wu ◽  
Yi Wang ◽  
Liang Yi Li
Keyword(s):  
Finite Element ◽  
Structural Analysis ◽  
Finite Element Model ◽  
Dynamic Analysis ◽  
Stress Analysis ◽  
Element Model ◽  
Original Structure ◽  
Static Stiffness ◽  
Stiffness Analysis ◽  
Weak Points

Universal shaft is widely used to transfer the torque and rotational movement from the drive shaft to the slave while position of one shaft can be changed. Crack used to appear in the fork part of the universal shaft in tests in a universal company. In order to solve this problem, in this paper, a finite element model of universal shaft was established with the application of Pro/E and ANSYS, and the static stiffness analysis, stress analysis and dynamic analysis were all applied in ANSYS. According to the results, the weak points were found and some improvements on the original structure were made.

Study on Finite Element Model for Splitting Capacity of Bamboo Culms

2014 ◽  
Vol 494-495 ◽  
pp. 558-562
Author(s):  
Zhang Rong Zhao ◽  
Wan Si Fu ◽  
Jian Bo Zhou ◽  
Wang Han
Keyword(s):  
Finite Element ◽  
Optimal Design ◽  
Fracture Mechanics ◽  
Brittle Fracture ◽  
Finite Element Model ◽  
Element Model ◽  
Test Method ◽  
Engineering Significance ◽  
Bamboo Structure ◽  
Brittle Fracture Mechanics

For the problem of bamboo structure safety caused by bamboo culms splitting, the bamboo culms splitting capacity test method is studied, bamboo culms splitting capacity finite element model based on brittle fracture mechanics is proposed in the work. The results calculated by FEM are consistent with the experimental results, and the error is in 20% or less. The bamboo culms splitting capacity finite element model established above can provide supports for bamboo culms wide engineering applications. The developed model has theory and engineering significance for digital bamboo building optimal design.

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