Engineering Calculator Development Using RSM for Dishwasher Tub Seal & Door Attributes

A Door sub-system serves as an interface between the customer and the Dishwasher (racks) and is operated when the customer needs to load or unload the utensils from a Dishwasher.

Appropriate door opening and closing forces along with proper sealing are essential prerequisites for the acceptable functioning of a Dishwasher and They qualify as very critical components for product quality. Door forces and sealing depends on multiple factors such as latch system, sealing interface, seal compressions, door and tub dimensional variations, etc. Dishwasher door & tub interface where dimensional variation is a considerably significant factor.

Modelling of the system is done using Finite Element Analysis (FEA) and a Design of Experiments (DOE) is performed to evaluate the system responses. Response Surface Models are generated for the seal and the door attributes considering the multiple factors and the design space exploration is done using the appropriate space filling algorithms in order to improve the accuracy of the response surface. This study also helps to understand the relationship between the multiple design parameters considered in the model and their effect on the door and seal forces.

The primary objective of this paper is to demonstrate how an engineering calculator is developed based on Response Surface Models (RSM) using a multidisciplinary design optimization platform, modeFRONTIER with CREO, Hypermesh, LS-DYNA and MathCAD integration. One engineering calculator was developed for each response including tub seal forces, door opening and closing forces, seal compressions at top and bottom, force gradients, door angle, etc.

The first engineering calculator is developed to understand the variation of tub seal design parameters on forces to compress the seal. Tub seal design parameters are very sensitive to the manufacturing process and result in a wider tolerance limits. This often results in large variation in seal forces. This calculator helps to predict the seal forces for a given value of a critical seal design parameter. The second calculator is developed for door attributes. This calculator helps to predict the door attributes for any given set of dimensions within specified limits. These calculators are embedded in Google sheets and democratized with design and supplier teams to help them gain additional insights without depending on computer simulations.