Finite element-based life prediction for high-temperature cyclic loading of a large superplastic forming die

2006 ◽  
Vol 41 (8) ◽  
pp. 539-559 ◽  
Author(s):  
J Shang ◽  
T. H Hyde ◽  
S. B Leen
Keyword(s):  
Finite Element ◽  
High Temperature ◽  
Cyclic Loading ◽  
Life Prediction ◽  
Superplastic Forming

Experimental and Numerical Characterisation of the Cyclic Thermo-Mechanical Behaviour of a High Temperature Forming Tool Alloy

2009 ◽  
Author(s):  
Aditya Deshpande ◽  
Sean B. Leen ◽  
Thomas H. Hyde
Keyword(s):  
High Temperature ◽  
Life Prediction ◽  
Creep Behaviour ◽  
Material Constant ◽  
Superplastic Forming ◽  
Material Model ◽  
Future Application ◽  
Temperature Dependent ◽  
Rate Dependent ◽  
Nickel Chromium

This paper describes high temperature cyclic and creep relaxation testing and modelling of a high nickel-chromium material (XN40F) for application to the life prediction of superplastic forming (SPF) tools. An experimental test programme to characterise the high temperature cyclic elastic-plastic-creep behaviour of the material over a range of temperatures between 20°C and 900°C is described. The objective of the material testing is the development of a high temperature material model for cyclic analyses and life prediction of superplastic forming (SPF) dies for SPF of titanium aerospace components. A two-layer visco-plasticity model which combines both creep and combined isotropic-kinematic plasticity is chosen to represent the material behaviour. The process of material constant identification for this model is presented and the predicted results are compared with the rate-dependent (isothermal) experimental results. The temperature-dependent material model is furthermore applied to simulative thermo-mechanical fatigue (TMF) tests, designed to represent the temperature and stress-strain cycling associated with the most damaging phase of the die cycle. The model is shown to give good correlation with the test data, thus vindicating future application of the material model in thermo-mechanical analyses of SPF dies, for distortion and life prediction.

scholarly journals Experimental and Numerical Characterization of the Cyclic Thermomechanical Behavior of a High Temperature Forming Tool Alloy

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
Sean B. Leen ◽  
Aditya Deshpande ◽  
Thomas H. Hyde
Keyword(s):  
High Temperature ◽  
Life Prediction ◽  
Material Constant ◽  
Superplastic Forming ◽  
Material Model ◽  
Fatigue Tests ◽  
Material Behavior ◽  
Future Application ◽  
Rate Dependent ◽  
Numerical Characterization

This paper describes high temperature cyclic and creep relaxation testing and modeling of a high nickel-chromium material (XN40F) for application to the life prediction of superplastic forming (SPF) tools. An experimental test program to characterize the high temperature cyclic elastic-plastic-creep behavior of the material over a range of temperatures between 20°C and 900°C is described. The objective of the material testing is the development of a high temperature material model for cyclic analyses and life prediction of SPF dies for SPF of titanium aerospace components. A two-layer viscoplasticity model, which combines both creep and combined isotropic-kinematic plasticity, is chosen to represent the material behavior. The process of material constant identification for this model is presented, and the predicted results are compared with the rate-dependent (isothermal) experimental results. The temperature-dependent material model is furthermore applied to simulative thermomechanical fatigue tests, designed to represent the temperature and stress-strain cycling associated with the most damaging phase of the die cycle. The model is shown to give good correlation with the test data, thus vindicating future application of the material model in thermomechanical analyses of SPF dies for distortion and life prediction.

Proposal of a new low-cycle fatigue life model for cast iron with room temperature calibration involving mean stress and high-temperature effects

2019 ◽  
Vol 233 (14) ◽  
pp. 5056-5073 ◽  
Author(s):  
Cristiana Delprete ◽  
Raffaella Sesana
Keyword(s):  
Finite Element ◽  
Cast Iron ◽  
High Temperature ◽  
Finite Element Model ◽  
Life Prediction ◽  
Low Cycle Fatigue ◽  
Element Model ◽  
Mean Stress ◽  
Exhaust Manifold ◽  
Cycle Fatigue

The paper presents and discusses a low-cycle fatigue life prediction energy-based model. The model was applied to a commercial cast iron automotive exhaust manifold. The total expended energy until fracture proposed by the Skelton model was modified by means of two coefficients which take into account of the effects of mean stress and/or mean strain, and the presence of high temperature. The model was calibrated by means of experimental tests developed on Fe–2.4C–4.6Si–0.7Mo–1.2Cr high-temperature-resistant ductile cast iron. The thermostructural transient analysis was developed on a finite element model built to overtake confidentiality industrial restrictions. In addition to the commercial exhaust manifold, the finite element model considers the bolts, the gasket, and a cylinder head simulacrum to consider the corresponding thermal and mechanical boundary conditions. The life assessment performance of the energy-based model with respect the cast iron specimens was compared with the corresponding Basquin–Manson–Coffin and Skelton models. The model prediction fits the experimental data with a good agreement, which is comparable with both the literature models and it shows a better fitting at high temperature. The life estimations computed with respect the exhaust manifold finite element model were compared with different multiaxial literature life models and literature data to evaluate the life prediction capability of the proposed energy-based model.

Finite Element Modelling and Experimental Testing of Thermomechanical Behaviour and Failure of Titanium Superplastic Forming Dies

2010 ◽  
Vol 433 ◽  
pp. 247-256 ◽  
Author(s):  
Sean B. Leen ◽  
Aditya A. Deshpande ◽  
Thomas H. Hyde
Keyword(s):  
High Temperature ◽  
Life Prediction ◽  
Experimental Testing ◽  
Creep Behaviour ◽  
Strain Range ◽  
Superplastic Forming ◽  
Nickel Chromium ◽  
Thermomechanical Behaviour ◽  
And Diffusion ◽  
Plastic Creep

This paper describes high temperature cyclic and creep relaxation testing and modelling of a high nickel-chromium material (XN40F) for application to life prediction of superplastic forming (SPF) tools. An experimental test programme to (i) characterise the high temperature cyclic elastic-plastic-creep behaviour of the material over a range of temperatures between 20oC and 900oC, including cyclic controlled strain-range tests at different strain-rates and creep relaxation tests, and (ii) identify the material constants relevant to thermo-mechanical fatigue (TMF) life prediction, is described. The objective of the material testing is the development of high temperature material and failure models for cyclic analyses and life prediction of SPF and diffusion bonding (DB) dies for titanium aerospace components.

Nonlocal Damage Modeling of Solder Joint Failure Under Thermomechanical Cyclic Loading

2021 ◽  
Author(s):  
Youssef Maniar ◽  
Alexander Kabakchiev ◽  
Marta Kuczynska ◽  
Masoomeh Bazrafshan ◽  
Peter Binkele ◽  
...  
Keyword(s):  
Finite Element ◽  
Cyclic Loading ◽  
Solder Joint ◽  
End Of Life ◽  
Damage Evolution ◽  
Life Prediction ◽  
Finite Element Simulations ◽  
Automotive Electronics ◽  
Localization Algorithm ◽  
Nonlocal Damage

Abstract The increasing electrified mobility poses a challenge on reliability prediction of automotive electronics, especially when safety systems are concerned. The use of finite element simulation for accurate end-of-life prediction of automotive electronic devices under harsh environmental loading condition is getting increasingly significant. In particular, solder interconnection failure is in focus when subjected to thermomechanical loads. During cyclic loading, the initial deformation behavior and subsequent solder degradation can be modeled within finite element simulations using material damage coupled deformation models. Such models employ the calculation of an internal damage state variable at integration point level as functions of time, temperature and governing stress-strain state. In this work, a thermodynamic consistent implicit nonlocal damage formulation is presented. This modeling approach allows absolute end-of-life prediction of different solder joint geometries under thermomechanical cyclic loading within finite element simulations. The presented nonlocal damage model consists of damage evolution with strain and stress state dependencies, such as stress multiaxiality. Furthermore, a numerical de-localization algorithm is proposed, in order to avoid instability of damage evolution caused by finite element mesh dependency. Finally, the advantages and implications of the nonlocal damage approach are discussed based on simulations of damage evolution in multiple solder joints of a QFN48 package under combined cyclic thermal and mechanical 4-point bending loading.

On Modeling Assumptions in Finite Element Analysis of Stents

2011 ◽  
Vol 5 (3) ◽  
Author(s):  
Nuno Rebelo ◽  
Rob Radford ◽  
Achim Zipse ◽  
Martin Schlun ◽  
Gael Dreher
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cyclic Loading ◽  
Life Prediction ◽  
Element Analysis ◽  
Computing Power ◽  
Full Analysis ◽  
Fabrication Tolerances ◽  
In Vivo Loading

Finite Element Analysis (FEA) of Nitinol medical devices has become prevalent in the industry. The analysis methods have evolved in time with the knowledge about the material, the manufacturing processes, the testing or in vivo loading conditions, and the FEA technologies and computing power themselves. As a result, some common practices have developed. This paper presents a study in which some commonly made assumptions in FEA of Nitinol devices were challenged and their effect was ascertained. The base model pertains to the simulation of the fabrication of a diamond shape stent specimen, followed by cyclic loading. This specimen is being used by a consortium of several stent manufacturers dedicated to the development of fatigue laws suitable for life prediction of Nitinol devices. The FEA models represent the geometry of the specimens built, for which geometrical tolerances were measured. These models use converged meshes, and all simulations were run in the FEA code Abaqus making use of its Nitinol material models. Uniaxial material properties were measured in dogbone specimens subjected to the same fabrication process as the diamond specimens. By convention, the study looked at computed geometry versus measured geometry and at the maximum principal strain amplitudes during cyclic loading. The first aspect studied was the effect of simulating a single expansion to the final diameter compared to a sequence of three partial expansions each followed by shape setting. The second aspect was to ascertain whether it was feasible to conduct the full analysis with a model based on the electropolished dimensions or should an electropolish layer be removed only at the end of fabrication, similar to the manufacturing process. Finally, the effect of dimensional tolerances was studied. For this particular geometry and loading, modeling of a single expansion made no discernable difference. The fabrication tolerances were so tight that the effect on the computed fatigue drivers was also very small. The timing of the removal of the electropolished layer showed an effect on the results. This may have been so, because the specimen studied is not completely periodic in the circumferential direction.

Analysis of Fatigue Life in High Temperature of W Pattern Sealing Rings Used in Aircraft Engine

2014 ◽  
Vol 496-500 ◽  
pp. 571-574
Author(s):  
Xi Chen ◽  
Yun Wang
Keyword(s):  
Finite Element ◽  
High Temperature ◽  
Fatigue Life ◽  
Cyclic Loading ◽  
Fatigue Test ◽  
Aircraft Engine ◽  
Finite Element Models ◽  
Flight Safety ◽  
Sectional Structure ◽  
High Temperature Gas

sealing rings used in aircraft engine are surrounded by high-temperature gas and cyclic loading when they are working. The reliability of its work directly affect flight safety and engines life. This paper framed some kind of W pattern sealing rings finite element models with different sectional structure size, first analyze them strength of structure in specific conditions, then simulate the fatigue life of them by using analysis methods of fatigue and parameters of fatigue test, finally we can get damage contours and fatigue life in high temperature of W pattern sealing rings theoretically, providing some theoretical reference of designing and manufacturing sealing rings.

scholarly journals On the Plastic Strain Accumulation in Notched Bars During High-Temperature Creep Dwell

2020 ◽  
Vol 36 (2) ◽  
pp. 167-176 ◽  
Author(s):  
Daniele Barbera ◽  
Haofeng Chen
Keyword(s):  
High Temperature ◽  
Cyclic Loading ◽  
Plastic Strain ◽  
Kinematic Hardening ◽  
High Temperature Creep ◽  
Strain Accumulation ◽  
Material Models ◽  
Cyclic Loading Condition ◽  
Hardening Material ◽  
Temperature Creep

ABSTRACTStructural integrity plays an important role in any industrial activity, due to its capability of assessing complex systems against sudden and unpredicted failures. The work here presented investigates an unexpected new mechanism occurring in structures subjected to monotonic and cyclic loading at high temperature creep condition. An unexpected accumulation of plastic strain is observed to occur, within the high-temperature creep dwell. This phenomenon has been observed during several full inelastic finite element analyses. In order to understand which parameters make possible such behaviour, an extensive numerical study has been undertaken on two different notched bars. The notched bar has been selected due to its capability of representing a multiaxial stress state, which is a practical situation in real components. Two numerical examples consisting of an axisymmetric v-notch bar and a semi-circular notched bar are considered, in order to investigate different notches severity. Two material models have been considered for the plastic response, which is modelled by both Elastic-Perfectly Plastic and Armstrong-Frederick kinematic hardening material models. The high-temperature creep behaviour is introduced using the time hardening law. To study the problem several results are presented, as the effect of the material model on the plastic strain accumulation, the effect of the notch severity and the mesh element type and sensitivity. All the findings further confirm that the phenomenon observed is not an artefact but a real mechanism, which needs to be considered when assessing off-design condition. Moreover, it might be extremely dangerous if the cyclic loading condition occurs at such a high loading level.

scholarly journals Low-Cycle Fatigue Crack Initiation Simulation and Life Prediction of Powder Superalloy Considering Inclusion-Matrix Interface Debonding

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4018
Author(s):  
Shuming Zhang ◽  
Yuanming Xu ◽  
Hao Fu ◽  
Yaowei Wen ◽  
Yibing Wang ◽  
...  
Keyword(s):  
Finite Element ◽  
Crack Initiation ◽  
Life Prediction ◽  
Damage Mechanics ◽  
Low Cycle Fatigue ◽  
Fatigue Crack Initiation ◽  
Fatigue Loading ◽  
Interface Debonding ◽  
Damage Evolution Equation ◽  
Finite Element Software

From the perspective of damage mechanics, the damage parameters were introduced as the characterizing quantity of the decrease in the mechanical properties of powder superalloy material FGH96 under fatigue loading. By deriving a damage evolution equation, a fatigue life prediction model of powder superalloy containing inclusions was constructed based on damage mechanics. The specimens containing elliptical subsurface inclusions and semielliptical surface inclusions were considered. The CONTA172 and TARGE169 elements of finite element software (ANSYS) were used to simulate the interfacial debonding between the inclusions and matrix, and the interface crack initiation life was calculated. Through finite element modeling, the stress field evolution during the interface debonding was traced by simulation. Finally, the effect of the position and shape size of inclusions on interface debonding was explored.

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