Lab Report : Spring Steel 60si2crva Foils With A Thickness Of 120 Îœ M
1526 WordsOct 4, 20177 Pages
Spring steel 60Si2CrVA foils with a thickness of 120 μm were purchased from Feintool Co, Shenzhen, Guangdong and used as the contacting foils. Foils with a diameter of 15 mm were cut out of the 60Si2CrVA foils. The under surface of these round foils were burnished with SiC papers and then polished with silk, and the thickness of contacting foils were reduced to ∼100 μm. After polishing, the round contacting foils were cleaned with acetone and then ethanol. The surface roughness of the polished surface of the contacting foil was ∼Ra 100 nm. A 3M black polyester tape (thickness of 80 μm) with a layer of glue (thickness of 10 μm) was then sticked to the upper surface of round contacting foils and covered with micro wave-like surface of…show more content…
In this study, ABAQUS was used to compute the dynamic evolution of the micro-feature when subjected to LSWP impact. The contact type of the contacting foil and the micro-feature is “surface-to-surface contact” with “non-friction.”
For the treated feature to be round, an axisymmetric 2D model was constructed to simulate the LSWP process. The model comprised CAX4R elements (Continuum, Axisymmetric, 4 nodes, Reduced integration), with a BIAS function in x-direction and z-direction to allow a denser mesh near the micro-feature. The element size and quantity are shown in Fig. 3. The element quantity of the model was 32856. A convergence study was also conducted. The element quantity of the contrastive models was 79200 and 472480. The results show that the maximum residual stress error is <2.16%, and the maximum displacement error was <1.78%, indicating that the results of this study were convergent. To remove the effect of the reflective shock wave, infinite elements were used at the bottom and the edge of the model (as shown in Fig. 3) [7–9]. The contacting foil is also meshed.
3.2 Calculation steps
The FEM calculation was performed in two steps, and ABAQUS/Explicit code was used in both the steps . During the first step, a pressure pulse (Fig. 4) is applied to the contacting foil, and the total step time is 300 ns with an increment of 1 ns. The purpose of this step is to master the dynamic