Evaluation of coupled finite element/meshfree method for a robust full-scale crashworthiness simulation of railway vehicles

Composite repair systems are used for many years to restore locally the pipe strength where it has been affected by damage such as wall thickness reduction due to corrosion, dent, lamination or cracks. Composite repair systems are commonly qualified, designed and installed according to ASME PCC2 code or ISO 24817 standard requirements. In both of these codes, the Maximum Allowable Working Pressure (MAWP) of the damaged section must be determined to design the composite repair. To do so, codes such as ASME B31G for example for corrosion, are used. The composite repair systems is designed to “bridge the gap” between the MAWP of the damaged pipe and the original design pressure. The main weakness of available approaches is their applicability to combined loading conditions and various types of defects. The objective of this work is to set-up a “universal” methodology to design the composite repair by finite element calculations with directly taking into consideration the loading conditions and the influence of the defect on pipe strength (whatever its geometry and type). First a program of mechanical tests is defined to allow determining all the composite properties necessary to run the finite elements calculations. It consists in compression and tensile tests in various directions to account for the composite anisotropy and of Arcan tests to determine steel to composite interface behaviors in tension and shear. In parallel, a full scale burst test is performed on a repaired pipe section where a local wall thinning is previously machined. For this test, the composite repair was designed according to ISO 24817. Then, a finite element model integrating damaged pipe and composite repair system is built. It allowed simulating the test, comparing the results with experiments and validating damage models implemented to capture the various possible types of failures. In addition, sensitivity analysis considering composite properties variations evidenced by experiments are run. The composite behavior considered in this study is not time dependent. No degradation of the composite material strength due to ageing is taking into account. The roadmap for the next steps of this work is to clearly identify the ageing mechanisms, to perform tests in relevant conditions and to introduce ageing effects in the design process (and in particular in the composite constitutive laws).

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Simulation of the nonplanar three-dimensional thermal cracking using the finite element-meshfree method

Applied Mathematical Modelling ◽

10.1016/j.apm.2021.06.011 ◽

2021 ◽

Author(s):

Lei Sun ◽

Siji Tao ◽

Xuhai Tang ◽

Quansheng Liu

Keyword(s):

Finite Element ◽

Three Dimensional ◽

Thermal Cracking ◽

Meshfree Method

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Finite Element Simulation of a Strong-Post W-Beam Guardrail System

SIMULATION ◽

10.1177/0037549702078010001 ◽

2002 ◽

Vol 78 (10) ◽

pp. 587-599 ◽

Cited By ~ 16

Author(s):

Ali O. Atahan

Keyword(s):

Finite Element ◽

Three Dimensional ◽

Full Scale ◽

Nonlinear Finite Element ◽

Crash Test ◽

Original Design ◽

Dynamic Interactions ◽

Crash Testing ◽

Element Simulation ◽

Test Requirements

Computer simulation of vehicle collisions has improved significantly over the past decade. With advances in computer technology, nonlinear finite element codes, and material models, full-scale simulation of such complex dynamic interactions is becoming ever more possible. In this study, an explicit three-dimensional nonlinear finite element code, LS-DYNA, is used to demonstrate the capabilities of computer simulations to supplement full-scale crash testing. After a failed crash test on a strong-post guardrail system, LS-DYNA is used to simulate the system, determine the potential problems with the design, and develop an improved system that has the potential to satisfy current crash test requirements. After accurately simulating the response behavior of the full-scale crash test, a second simulation study is performed on the system with improved details. Simulation results indicate that the system performs much better compared to the original design.

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Use of DNVGL-RP-C203 for Determining the Fatigue Capacity of Connectors

10.1115/omae2021-62880 ◽

2021 ◽

Author(s):

Anthony Muff ◽

Anders Wormsen ◽

Torfinn Hørte ◽

Arne Fjeldstad ◽

Per Osen ◽

...

Keyword(s):

Finite Element ◽

Fatigue Testing ◽

Experimental Testing ◽

High Strength ◽

Element Model ◽

Fatigue Analysis ◽

Full Scale ◽

The Finite Element Model

Abstract Guidance for determining a S-N based fatigue capacity (safe life design) for preloaded connectors is included in Section 5.4 of the 2019 edition of DNVGL-RP-C203 (C203-2019). This section includes guidance on the finite element model representation, finite element based fatigue analysis and determination of the connector design fatigue capacity by use of one of the following methods: Method 1 by FEA based fatigue analysis, Method 2 by FEA based fatigue analysis and experimental testing and Method 3 by full-scale connector fatigue testing. The FEA based fatigue analysis makes use of Appendix D.2 in C203-2019 (“S-N curves for high strength steel applications for subsea”). Practical use of Section 5.4 is illustrated with a case study of a fatigue tested wellhead profile connector segment test. Further developments of Section 5.4 of C203-2019 are proposed. This included acceptance criteria for use of a segment test to validate the FEA based fatigue analysis of a full-scale preloaded connector.

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A Hybrid Supervised Deep Learning and Nonlinear Finite Element Framework for Efficient Fatigue Life Predictions of Rotary Shouldered Threaded Connections

Volume 12: Mechanics of Solids, Structures, and Fluids ◽

10.1115/imece2020-24047 ◽

2020 ◽

Author(s):

Fei Song ◽

Ke Li

Keyword(s):

Finite Element ◽

Deep Learning ◽

Fatigue Life ◽

Learning Algorithm ◽

Fatigue Tests ◽

Full Scale ◽

Remaining Useful Life ◽

Nonlinear Finite Element ◽

Threaded Connections ◽

Life Predictions

Abstract In this paper, a hybrid computational framework that combines the state-of-the art machine learning algorithm (i.e., deep neural network) and nonlinear finite element analysis for efficient and accurate fatigue life prediction of rotary shouldered threaded connections is presented. Specifically, a large set of simulation data from nonlinear FEA, along with a small set of experimental data from full-scale fatigue tests, constitutes the dataset required for training and testing of a fast-loop predictive model that could cover most commonly used rotary shouldered connections. Feature engineering was first performed to explore the compressed feature space to be used to represent the data. An ensemble deep learning algorithm was then developed to learn the underlying pattern, and hyperparameter tuning techniques were employed to select the learning model that provides the best mapping, between the features and the fatigue strength of the connections. The resulting fatigue life predictions were found to agree favorably well with the experimental results from full-scale bending fatigue tests and field operational data. This newly developed hybrid modeling framework paves a new way to realtime predicting the remaining useful life of rotary shouldered threaded connections for prognostic health management of the drilling equipment.

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STUDY OF THE FIRE PERFORMANCE OF HYBRID STEEL-TIMBER CONNECTIONS WITH FULL-SCALE TESTS AND FINITE ELEMENT MODELLING

Applications of Structural Fire Engineering ◽

10.14311/asfe.2015.039 ◽

2016 ◽

Author(s):

Aaron O. Akotuah ◽

Sabah G. Ali ◽

Jeffrey Erochko ◽

Xia Zhang ◽

George V. Hadjisophocleous

Keyword(s):

Finite Element ◽

Load Ratio ◽

Full Scale ◽

Test Results ◽

Structural Members ◽

Fire Performance ◽

Shear Connection ◽

Timber Connections ◽

Full Scale Tests ◽

Connection Design

Connection design is critical in timber buildings since the connections tend to have lower strength than the structural members themselves and they tend to fail in a brittle manner. The effect of connection geometry on the fire performance of a hybrid steel-timber shear connection is investigated by full-scale testing. These tests were conducted by exposing the test specimens to the standard time-temperature curve defined by CAN/ULC-S101 (CAN/ULC-S101, 2007). Test results showed that the fire resistance of these connections depends on the load ratio, the type of connection and the relative exposure of the steel plate to fire. Finite element models of the connections under fire were constructed using ABAQUS/CAE and these were validated using the test results. These numerical model results correlate well with test results with ±8.32% variation.

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Finite Element Analysis of the Rolling Contact Fatigue Life of Railcar Wheels

Materials Science Forum ◽

10.4028/www.scientific.net/msf.575-578.1461 ◽

2008 ◽

Vol 575-578 ◽

pp. 1461-1466

Author(s):

Byeong Choon Goo ◽

Jung Won Seo

Keyword(s):

Heat Treatment ◽

Residual Stress ◽

Finite Element Analysis ◽

Finite Element ◽

Fatigue Life ◽

Contact Fatigue ◽

Rolling Contact ◽

Element Analysis ◽

Railway Vehicles ◽

Contact Fatigue Life

Railcar wheels and axles belong to the most critical components in railway vehicles. The service conditions of railway vehicles have been more severe in recent years due to speed-up. Therefore, a more precise evaluation of railcar wheel life and safety has been requested. Wheel/rail contact fatigue and thermal cracks due to braking are two major mechanisms of the railcar wheel failure. One of the main sources influencing on the contact zone failure is residual stress. The residual stress in wheels formed during heat treatment in manufacturing changes in the process of braking. Thus the fatigue life of railcar wheels should be estimated by considering both thermal stress and rolling contact. Also, the effect of residual stress variation due to manufacturing process and braking process should be included in simulating contact fatigue behavior. In this paper, an evaluation procedure for the contact fatigue life of railcar wheels considering the effects of residual stresses due to heat treatment, braking and repeated contact load is proposed. And the cyclic stressstrain history for fatigue analysis is simulated by finite element analysis for the moving contact load.

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Embankment on sludge: predicted and observed performances

Canadian Geotechnical Journal ◽

10.1139/t07-004 ◽

2007 ◽

Vol 44 (5) ◽

pp. 545-563 ◽

Cited By ~ 13

Author(s):

Tien H Wu ◽

Steven Z Zhou ◽

Stephan M Gale

Keyword(s):

Finite Element ◽

Water Treatment ◽

Input Data ◽

Bayesian Updating ◽

Full Scale ◽

The Finite Element Method ◽

Water Treatment Sludge ◽

History Of ◽

Finite Element Prediction ◽

Test Embankment

The case history of an embankment built over soft water-treatment sludge is presented. To assure that the sludge would consolidate and gain strength as predicted, a test embankment was built. The observed performance of the test embankment was compared with the predicted performance to verify and modify design assumptions. The results were used to design and construct the full-scale embankment. The finite element method and the critical state model were used to predict the performances of the test embankment and the full-scale embankment. Bayesian updating and system identification were used to update the material properties used in the prediction for the test embankment. The updated properties were then used to update the prediction for the test embankment and to predict the performance of the full-scale embankment. These predictions were compared with the observed performances to evaluate the accuracies of the predictions with different input data. Efforts were made to identify factors that cause differences between predicted and measured performances.Key words: Bayesian updating, consolidation, finite-element prediction, shear strength, stability, water-treatment sludge.

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