Characterisation of the behaviour of welded aluminium structures under dynamic loading
| Autor: | Huon Bornstein, Norman Herzig, Eric Yang, Emily Frain, Brodie McDonald, Daniel De Oliveira Damas |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Heat-affected zone
Digital image correlation Physics QC1-999 technology industry and agriculture chemistry.chemical_element 02 engineering and technology Welding respiratory system 021001 nanoscience & nanotechnology law.invention 020303 mechanical engineering & transports 0203 mechanical engineering chemistry law Dynamic loading Aluminium Ultimate tensile strength Composite material 0210 nano-technology Porosity Failure mode and effects analysis |
| Zdroj: | EPJ Web of Conferences, Vol 183, p 01038 (2018) |
| Popis: | The presence and quality of welds in metallic structures has the ability to influence their likelihood of failure under dynamic loading. This investigation focused on characterising the behaviour of a welded aluminium structure. Samples were taken from the parent metal, heat affected zone (HAZ) and the weld bead and high strain rate characterisation testing was performed to determine the Johnson-Cook (JC) strength and failure model parameters for each material. However, significant scatter was found in the data for the weld bead due to porosity within the samples. Additional tensile tests were performed using a rotating fly wheel machine with four larger samples, which were machined from the welded aluminium structure and contained HAZs on either side of the weld bead, located in the centre of the specimen. Three of the four samples had the weld bead ground flush to the level of the base plate. Digital image correlation was used to determine the surface strain within each region of the sample and identified significant strain localisation at the interface between the weld metal and the HAZ, as well as within the weld bead. Comparisons between the ground welded specimens and those with the weld reinforcement showed a different failure mode between the two specimens. For the ground specimens, the strain localisation in the weld bead initiated failure prior to the strain localisation occurring at the interface between the weld bead and HAZ. Sectioning of the welds indicated that the strain localisation in the weld bead may have been caused by significant levels of porosity within the weld bead. Preliminary numerical simulations of the ground specimens indicated that the force-time history could be well captured. However, as the strain localisation due to porosity is not captured using a JC model, in addition to the scatter in the characterisation data for the weld bead, failure was not accurately predicted numerically. |
| Databáze: | OpenAIRE |
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