An improved nano-scale material model applied in axial-crushing analyses of square hollow section aluminium profiles

Hoang, Nguyen-Hieu; Hopperstad, Odd Sture; Myhr, Ole Runar; Marioara, Calin Daniel; Langseth, Magnus

doi:10.1016/j.tws.2015.02.013

Cited by 15 publications

(11 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The use of a precipitate-based yield stress is consistent with other work [54,55] and the validation of the model (Fig. 8) reveals a close correspondence to test data.…”

Section: Discussionsupporting

confidence: 87%

A process-structure-property model for welding of 9Cr power plant components: The influence of welding process temperatures on in-service cyclic plasticity response

Ardghail

Harrison

Leen

2019

International Journal of Pressure Vessels and Piping

View full text Add to dashboard Cite

A process-structure-property methodology is presented for welding of 9Cr steels under representative flexible operating conditions for a typical thermal power plant girth-welded pipe. The welding-induced evolution of microstructural variables is represented via (i) a solid-state phase transformation model for martensite-austenite transformation and (ii) empirical equations for prior austenite grain size, martensite lath width, hardness and M23C6 precipitate diameter and area fraction, calibrated from published heat treatment data.The temperature-dependent, physically-based, unified viscoplastic constitutive model, which includes a fatigue damage initiation criterion, is based on dislocation density evolution and is validated against high temperature cyclic plasticity data at a range of relevant temperatures for parent material P91, including combined isotropic-kinematic hardening effects. This model is shown to successfully predict weld-life reduction factor for cross-weld tests. The effects of key welding process variables on the microstructure gradient in the heat-affected zone, and associated thermo-mechanical, cyclic plasticity response are assessed. The inter-critical and fine-grained heat-affected zones are identified as the critical regions, consistent with observed plant experience. Increasing post-weld heat-treatment temperature from 760 o C from 780 o C is predicted to be detrimental due to increased precipitate coarsening. In contrast, increasing preheat and interpass temperature from 350 o C to 400 o C is predicted to be beneficial due to increased hardness in the critical regions.

show abstract

“…The use of a precipitate-based yield stress is consistent with other work [54,55] and the validation of the model (Fig. 8) reveals a close correspondence to test data.…”

Section: Discussionsupporting

confidence: 87%

A process-structure-property model for welding of 9Cr power plant components: The influence of welding process temperatures on in-service cyclic plasticity response

Ardghail

Harrison

Leen

2019

International Journal of Pressure Vessels and Piping

View full text Add to dashboard Cite

show abstract

“…Note that the justification of implementing Eq. [10] in NaMo-Version 2 relies solely on the fact that it has proved to work well in many other situations, [21][22][23][24][25][26][27][28][29]42,48] since the assumption of linear additive strength contributions is just one of several possible options to choose from when calculating r y . [1,2,65] In the original yield strength model, a constant Taylor factor of 3.1 is assumed when calculating r y .…”

Section: Framework For Calculating the Macroscopic Yield Strengthmentioning

confidence: 99%

“…[20][21][22] Later, it has been renamed the nanostructure model (NaMo) in order to reach out to a wider audience and make the work accessible to people with a background in finite element simulations and advanced structural analyses as well. [23][24][25][26][27] Referring to Figure 1, NaMo-Version 1 divides the age-hardening process into two main stages, i.e., the solution heat treatment (SHT) stage and the artificial aging (AA) stage, based on a simplified description of the artificial aging reaction sequence. [20][21][22] At the same time, the important alloy composition dependence of the artificial aging reactions is accounted for through the use of a separate thermodynamic (TD) model, which provides quantitative information about the thermal stability of the different stable and metastable precipitates involved.…”

Section: Introductionmentioning

confidence: 99%

“…At any time during the artificial aging process, the resulting stress-strain curve at RT can be calculated from the integrated yield strength and work-hardening models for different thermomechanical treatments and alloy compositions and used in more advanced numerical analyses of the mechanical integrity of real aluminum structures. [22][23][24][25][26][27]29,30] In the following, both the new and the adapted models being implemented in NaMo-Version 2 will be described more in detail. Then the experimental program, which has been designed to generate data for calibration and validation of the same models, is outlined.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

An Extended Age-Hardening Model for Al-Mg-Si Alloys Incorporating the Room-Temperature Storage and Cold Deformation Process Stages

Myhr

Grong

Schäfer

2015

Metall Mater Trans A

Self Cite

View full text Add to dashboard Cite

In this article, a new age-hardening model for Al-Mg-Si alloys is presented (named NaMo-Version 2), which takes into account the combined effect of cold deformation and prolonged room-temperature storage on the subsequent response to artificial aging. As a starting point, the original physical framework of NaMo-Version 1 is revived and used as a basis for the extension. This is permissible, since a more in-depth analysis of the underlying particle-dislocation interactions confirms previous expectations that the simplifying assumption of spherical precipitates is not crucial for the final outcome of the calculations, provided that the yield strength model is calibrated against experimental data. At the same time, the implementation of the Kampmann-Wagner formalism means that the different microstructure models can be linked together in a manner that enforces solute partitioning and competition between the different hardening phases which form during aging (e.g., clusters, b¢¢ and b¢). In a calibrated form, NaMo-Version 2 exhibits a high degree of predictive power, as documented by comparison with experiments, using both dedicated nanostructure and yield strength data as a basis for the validation. Hence, the model is deemed to be well-suited for simulation of thermomechanical processing of Al-Mg-Si alloys involving cold-working operations like sheet forming and stretch bending in combination with heat treatment and welding.

show abstract

“…A nanostructure-based finite element simulation model was developed and showed excellent prediction of the experimentally obtained force-deformation curves as well as the energy absorption capacity. Hoang et al [9] studied the effect of different types of cooling after a solid solution on the axial crushing performance of AA6060 aluminum alloy square hollow section profiles. They observed that the effect of the cooling rate on the absorption of the crushing energy of the under-aging and over-aging profiles was insignificant, but it has a great influence on the peak-aging profiles.…”

Section: Introductionmentioning

confidence: 99%

Effect of Zn and Mg Content on Crashworthiness of Al-Zn-Mg Alloy Thin-Walled Square Extrusions

et al. 2020

View full text Add to dashboard Cite

The effects of Zn and Mg content in thin-walled square extrusions of Al-Zn-Mg alloys on its crashworthiness were investigated, and the correlation between the crushing properties, mechanical properties, and microstructures of the profiles were investigated. The results showed that the strength and the compression properties were gradually increased with a decrease in the Zn/Mg ratios (from 12.48 to 4.57). When the Zn/Mg ratio is lower (less than 6.29), an increase in the Mg content simultaneously improves the alloy strength and the compression properties. An increase in Zn content (from 5.07 to 6.77) can improve the strength of the alloy however, it does not affect the compression properties. However, the higher Zn contents (6.77%) would lead to cracking in advance during the compressing, which reduces the compression energy absorption capacities of the product. Therefore, in order to obtain higher strength and excellent compression properties, the Zn/Mg ratio should be reduced. For the upper limit, the Zn content should not be too high (less than 6.77), as this may lead to early cracking and failure. For the lower limit, the Mg content should be higher (more than 0.91) to make sure that the alloy has excellent compression properties and higher strength.

show abstract

An improved nano-scale material model applied in axial-crushing analyses of square hollow section aluminium profiles

Cited by 15 publications

References 15 publications

A process-structure-property model for welding of 9Cr power plant components: The influence of welding process temperatures on in-service cyclic plasticity response

A process-structure-property model for welding of 9Cr power plant components: The influence of welding process temperatures on in-service cyclic plasticity response

An Extended Age-Hardening Model for Al-Mg-Si Alloys Incorporating the Room-Temperature Storage and Cold Deformation Process Stages

Effect of Zn and Mg Content on Crashworthiness of Al-Zn-Mg Alloy Thin-Walled Square Extrusions

Contact Info

Product

Resources

About