The hardness of five acrylic artificial teeth brands marketed in Bandung city

The acrylic artificial teeth are still among the most frequently used artificial teeth. Some commercial brands marketed in Bandung claim that their products have met the existing standards. However, those brands do not give any mechanical property data, including data on hardness. The ADA specification standard no. 15 requires a hardness of minimum 15.00 KHN for acrylic artificial teeth. The aim of this study is to find out which acrylic artificial teeth actually have a standardized hardness value. The study is an analytical descriptive study, which is performed on 5 brands of acrylic artificial teeth marketed in Bandung. From each brand, 4 teeth were sampled and receive 10 indentation spots on the upper and lower surfaces. It is concluded that the five acrylic artificial teeth brands have met the ADA specification standard no. 15 and there are differences in hardness values among the five brands.

Investigation of High Temperature Mechanical Properties for Improved Finite Element Analysis Simulations of Forged Railroad Wheels

Finite element analysis (FEA) programs depend on accurate evaluation of mechanical and physical properties for determination of thermo-mechanical characteristics of wheel designs. For wheel residual stress analyses, both property types are equally important. Also important is knowledge of the anisotropy of properties in a design. For this paper, the authors tested AAR M107/M208 Class “C” steel ingot material and an as-forged (but untreated) wheel. The information presented includes elevated temperature mechanical properties of ingot material taken in circumferential, radial and axial orientations at two depth positions. High temperature mechanical property data (not currently found in the literature beyond 1800F) is also included for the ingot steel. Untreated as-forged AAR Class “C” material mechanical properties were evaluated at temperatures up to 2000F, and at the rim, plate and hub locations. High temperature mechanical property data for heat treated micro-alloy AAR Class “C” wheels are also presented.