The size effect on fatigue strength of mild steel

Abstract

Fatigue evaluates the effects of material shape, surface condition, stress level, material size and related factors on fatigue life of metallic materials. These studies focused on experimental analysis to compare the effect of a small specimen to that of a larger specimen size of diameter 1mm, 2mm, and 8mm of Mild Steel. This paper will first define the properties of Mild Steel by using the Tensile Test and also The Hardness Test. The SEM machine also had been use to define Chemical Composition of the material by using the EDX technique. After defined the properties of Mild Steel, the Fatigue Test is then done for Mild Steel with different size of diameter 1mm, 2mm, and 8mm. For specimen 1mm and 2mm, the test is done by Micro Fatigue Testing Machine. Meanwhile for the specimen 8mm, the test is done by Cantilever Rotating Bending Fatigue Testing Machine. Lastly the Scanning Electron Microscopy (SEM) has been used to capture the picture of the crack surface which are use to find the crack and the length of the crack.