ATLAS+ European Project: Prediction of Large Ductile Tearing in Piping Using Local Approach

2019 ◽  
Author(s):  
Arnaud Blouin ◽  
Stéphane Marie ◽  
Al Mahdi Remmal
Keyword(s):  
Laboratory Tests ◽  
Damage Model ◽  
Experimental Tests ◽  
Compact Tension ◽  
Theoretical Background ◽  
Bending Test ◽  
Continuum Damage ◽  
Single Edge ◽  
Local Approach ◽  
Ductile Tearing

Abstract In the frame of the European ATLAS+ project it was decided to evaluate if a continuum damage model can simulate a four-points beading test on a ferritic pipe (A508 type). In this paper, the theoretical background is presented. Then, based on finite elements analyses, the GTN model damage parameters are defined by simulating laboratory tests on Notched Tensile specimens and Compact Tension specimens. From that identification, experimental tests on Single Edge Notched Tensile specimens are simulated in order to verify if the previous parameters are able to describe a large ductile tearing. Finally, the four points bending test simulation is also presented.

ATLAS+ European Project: Prediction of Large Ductile Tearing in Austenitic Piping Using Local Approach

2020 ◽  
Author(s):  
Arnaud Blouin ◽  
Stéphane Marie
Keyword(s):  
Welded Joint ◽  
Damage Model ◽  
Compact Tension ◽  
Compact Tension Specimen ◽  
Theoretical Background ◽  
Bending Test ◽  
Continuum Damage ◽  
Tension Specimen ◽  
Local Approach ◽  
Ductile Tearing

Abstract In the frame of the European ATLAS+ project it was decided to evaluate if a continuum damage model can simulate a four-points bending test on an austenitic pipe (316L type) with an aged welded joint. In this paper, the theoretical background is presented. Then, based on finite elements analyses, the GTN model damage parameters are defined by simulating laboratory tests on Notched Tensile specimens and Compact Tension specimen. Finally, the four points bending test simulation is also presented.

Numerical Investigation of Ductile Fracture in Pipelines Under Complex Loading Using a Phenomenological Damage Model

2021 ◽  
Author(s):  
Iago S. Santos ◽  
Diego F. B. Sarzosa
Keyword(s):  
Ductile Fracture ◽  
Mechanical Response ◽  
Numerical Study ◽  
Damage Model ◽  
Stress Triaxiality ◽  
Numerical Procedure ◽  
Complex Loading ◽  
Experimental Tests ◽  
Compact Tension ◽  
Axial Tensile

Abstract This paper presents a numerical study on pipes ductile fracture mechanical response using a phenomenological computational damage model. The damage is controlled by an initiation criterion dependent on the stress triaxiality and the Lode angle parameter, and a post-initiation damage law to eliminate each finite element from the mesh. Experimental tests were carried out to calibrate the elastoplastic response, damage parameters and validate the FEM models. The tested geometries were round bars having smooth and notched cross-section, flat notched specimens under axial tensile loads, and fracture toughness tests in deeply cracked bending specimens SE(B) and compact tension samples C(T). The calibrated numerical procedure was applied to execute a parametric study in pipes with circumferential surface cracks subjected to tensile and internal pressure loads simultaneously. The effects of the variation of geometric parameters and the load applications on the pipes strain capacity were investigated. The influence of longitudinal misalignment between adjacent pipes was also investigated.

Using Virtual Testing to Study the Influence of Constraint on Fracture Properties

2018 ◽  
Author(s):  
Christopher Seal ◽  
Robert Ainsworth
Keyword(s):  
Failure Strain ◽  
Fracture Behaviour ◽  
Damage Model ◽  
Compact Tension ◽  
Single Edge ◽  
Fracture Properties ◽  
Test Pieces ◽  
Sharp Crack ◽  
Edge Notch ◽  
Ct Test

This paper presents a study in which the influence of constraint is investigated using a ductile damage model based on a stress modified failure strain. This model, proposed by Oh et al, has been used to successfully predict the J-R curve of standard compact tension (CT) test pieces for a range of different materials. Further work has shown how the model can also predict the fracture behaviour of non-standard CT test specimens, in which a blunt notch is used in place of a sharp crack. Continuing on from this work, the paper predicts the J-R curves of single edge notch tension (SET) test pieces with both a sharp crack and blunt notches.

Numerical Simulation on Projectile Penetrating Wedge Concrete

2011 ◽  
Vol 261-263 ◽  
pp. 166-170
Author(s):  
Guo Ping Jiang ◽  
Shi Huan ◽  
Chu Jie Jiao ◽  
Wei Jun Tao
Keyword(s):  
Numerical Simulation ◽  
Laboratory Tests ◽  
Damage Mechanics ◽  
Damage Model ◽  
Research Work ◽  
Continuum Damage Mechanics ◽  
Simulation Method ◽  
Continuum Damage ◽  
Penetration Process ◽  
Concrete Model

The numerical simulation method has been used to projectile penetrating concrete for many years. However, most previous research work has concentrated on the cuboids concrete model. Very few studies have been conducted to investigate the penetration process of complex concrete model. In this paper, numerical simulations of laboratory tests are conducted to show the penetration process of wedge concrete model. A double scalar damage model based on the concept of continuum damage mechanics is applied to modeling the failure of concrete. In the numerical model of wedge concrete, the wedges with different angles are modeled.

Geometry Transferability of Lemaitre's Continuum Damage Mechanics Model in the Plane Stress Specimens

2013 ◽  
Vol 592-593 ◽  
pp. 266-270 ◽  
Author(s):  
Nima Allahverdizadeh ◽  
Andrea Manes ◽  
Marco Giglio ◽  
Andrea Gilioli
Keyword(s):  
Plane Stress ◽  
Damage Mechanics ◽  
Numerical Models ◽  
Damage Model ◽  
High Strength ◽  
Experimental Tests ◽  
Continuum Damage Mechanics ◽  
Failure Behavior ◽  
Continuum Damage ◽  
Damage Models

Different damage mechanics models have been proposed by researchers to calibrate the failure behavior of materials. Continuum damage mechanics (CDM) models are one of the main categories of damage models that can be exploited in numerical simulations. In this paper Lemaitres damage model, has been applied to finite element models of flat specimens. These models allow assessing the geometry transferability of the previously calibrated CDM model investigating in different geometry and loading conditions. Four different types of plane stress specimens have been designed to get different stress triaxialities which cover shear dominant and high triaxiality failure. Experimental tests were also done and the obtained data were critically compared with the results from numerical models. The tested material is Ti-6Al-4V titanium alloy which is a widely used material in aerospace industry because of its high strength and low density.

Cross-Ply Laminates under Static Three-Point Bending: A Numerical Development Model

2012 ◽  
Vol 498 ◽  
pp. 42-54 ◽  
Author(s):  
S. Benbelaid ◽  
B. Bezzazi ◽  
A. Bezazi
Keyword(s):  
Numerical Model ◽  
Damage Mechanics ◽  
Progressive Failure ◽  
Damage Model ◽  
Continuum Damage Mechanics ◽  
Failure Criteria ◽  
Continuum Damage ◽  
Damage Development ◽  
Element Analysis ◽  
Progressive Failure Analysis

This paper considers damage development mechanisms in cross-ply laminates using an accurate numerical model. Under static three points bending, two modes of damage progression in cross-ply laminates are predominated: transverse cracking and delamination. However, this second mode of damage is not accounted in our numerical model. After a general review of experimental approaches of observed behavior of laminates, the focus is laid on predicting laminate behavior based on continuum damage mechanics. In this study, a continuum damage model based on ply failure criteria is presented, which is initially proposed by Ladevèze. To reveal the effect of different stacking sequence of the laminate; such as thickness and the interior or exterior disposition of the 0° and 90° oriented layers in the laminate, an equivalent damage accumulation which cover all ply failure mechanisms has been predicted. However, the solution algorithm using finite element analysis which implements progressive failure analysis is summarized. The results of the numerical computation have been justified by the previous published experimental observations of the authors.

Identification of Tire Model Parameters Through Full Vehicle Experimental Tests

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Francesco Braghin ◽  
Federico Cheli ◽  
Edoardo Sabbioni
Keyword(s):  
Laboratory Tests ◽  
Experimental Tests ◽  
Contact Forces ◽  
Lateral Acceleration ◽  
Design Stage ◽  
Model Parameters ◽  
Tire Model ◽  
Identification Procedure ◽  
Sideslip Angle ◽  
Tyre Model

Individual tire model parameters are traditionally derived from expensive component indoor laboratory tests as a result of an identification procedure minimizing the error with respect to force and slip measurements. These parameters are then transferred to vehicle models used at a design stage to simulate the vehicle handling behavior. A methodology aimed at identifying the Magic Formula-Tyre (MF-Tyre) model coefficients of each individual tire for pure cornering conditions based only on the measurements carried out on board vehicle (vehicle sideslip angle, yaw rate, lateral acceleration, speed and steer angle) during standard handling maneuvers (step-steers) is instead presented in this paper. The resulting tire model thus includes vertical load dependency and implicitly compensates for suspension geometry and compliance (i.e., scaling factors are included into the identified MF coefficients). The global number of tests (indoor and outdoor) needed for characterizing a tire for handling simulation purposes can thus be reduced. The proposed methodology is made in three subsequent steps. During the first phase, the average MF coefficients of the tires of an axle and the relaxation lengths are identified through an extended Kalman filter. Then the vertical loads and the slip angles at each tire are estimated. The results of these two steps are used as inputs to the last phase, where, the MF-Tyre model coefficients for each individual tire are identified through a constrained minimization approach. Results of the identification procedure have been compared with experimental data collected on a sport vehicle equipped with different tires for the front and the rear axles and instrumented with dynamometric hubs for tire contact forces measurement. Thus, a direct matching between the measured and the estimated contact forces could be performed, showing a successful tire model identification. As a further verification of the obtained results, the identified tire model has also been compared with laboratory tests on the same tire. A good agreement has been observed for the rear tire where suspension compliance is negligible, while front tire data are comparable only after including a suspension compliance compensation term into the identification procedure.

Modified Dyson Continuum Damage Model for Austenitic Steel Alloy

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Seok Jun Kang ◽  
Hoomin Lee ◽  
Jae Boong Choi ◽  
Moon Ki Kim
Keyword(s):  
Damage Model ◽  
Life Time ◽  
Continuum Damage ◽  
Creep Life ◽  
Creep Tests ◽  
Continuum Damage Model ◽  
Thermal Plant ◽  
Uniaxial Creep ◽  
Term Creep

Ultrasuper critical (USC) thermal plants are now in operation around the globe. Their applications include superheaters and reheaters, which generally require high temperature/pressure conditions. To withstand these harsh conditions, an austenitic heat-resistant HR3C (ASME TP310NbN) steel was developed for metal creep resistance. As the designed life time of a typical thermal plant is 150,000 h, it is very important to predict long-term creep behavior. In this study, a three-state variable continuum damage model (CDM) was modified for better estimation of long-term creep life. Accelerated uniaxial creep tests were performed to determine the material parameters. Also, the rupture type and microstructural precipitation were observed by scanning electron microscopy. The creep life of HR3C steel was predicted using only relatively short-term creep test data and was then successfully verified by comparison with the long-term creep data.

Sign in / Sign up

Export Citation Format

Share Document