This paper presents the dimensional accuracy of the wax replicas generated by room temperature vulcanisation (RTV) silicon rubber moulding for stepped bar pattern to be used in investment casting. The main purpose of this research work is to investigate the effect of process parameters on dimensional accuracy and test its practical implication in RTV moulding technique. To study the influence of process factors, a 3-factor 4-level (L16) orthogonal array experiment is designed as per Taguchi method and the result is reported. A case study for research of dimensional accuracy of wax patterns created by RTV silicone rubber mould had not been attempted as earlier for stepped bars. As this appends an additional stage in the tooling process, it is evident to estimate and predict the dimensional deviation from RP model and its wax replica. Experimental results show the dimensional accuracy in RTV technique is accurately the same as in traditional moulding. It was realised that RTV tooling technique can be used efficiently to produce wax patterns at optimum condition in investment casting.
The current study aims at design exploration of a structural steel spring plate using FEM and design of experiments (DoE). Box-Behnken design (BBD) was used for DoE, and FEM was used to model and solve various design points. First, structural analyses of the spring plate were performed to determine the maximum deformation and von-Mises stress in the model. The study considered bend radius (P1), hole spacing (P6), and internal and external thicknesses (P11, P12) as input parameters. Twenty-five BBD-based numerical experiments were run in ANSYS WB. Regression analysis yielded accurate output parameter regression models based on input parameters. ANOVA was used to determine the importance of each input parameter on the output parameters. Response surface methodology (RSM) was used to determine the change in response variable vs. input parameters. The goodness-of-fit analysis showed good agreement between RSM-predicted and FEM-determined output parameters.
