A SYSTEMATIC METHODOLOGY FOR FATIGUE ANALYSIS OF MACHINE ELEMENTS WITH CHARACTERIZED DYNAMIC LOADS
thesisposted on 10.06.2019 by Rahul Mula
In order to distinguish essays and pre-prints from academic theses, we have a separate category. These are often much longer text based documents than a paper.
Fatigue analysis is essential for the optimization of products subjected to dynamic loads. However, a number of fatigue analysis theories have been developed, how to apply an established method in real-world product designs is not a trivial task. Most of small or medium sized enterprises (SMEs) still rely heavily on the experiments to evaluate the fatigue lives of products. Among existing fatigue design methods (i.e., experiments, analytical methods, and simulations), the simulation-based methods have the advantages of low cost, low risk environment and enable a designer to determine the accuracy and performance of a product design without building physical prototypes. Regarding the methodologies for fatigue analysis, some identified challenges are (1) the characterization of dynamic loads, (2) the formulation of finite element models which can be aligned with applications or testing scenarios, and (3) the verification and validation of simulations. To make a simulation-based fatigue analysis more practical for real-world product designs, the solutions to the aforementioned problems must be found. This thesis aims to establish a systematic methodology to perform the fatigue analysis for product design with any material, carbon steel material is used for the present case study to illustrate and verify the proposed methodology for fatigue analysis. Major tasks involved in this thesis study are: 1).The method for the characterization of dynamic loads. It is a numerical method to simulate the kinematic and dynamic behaviors subjected to the given motion, and it is expected to extract interacting dynamic forces of components to be analyzed. 2).The systematic method and procedure to formulate the problem of fatigue analysis as a finite element analysis model and find the solution of fatigue life of product.3).The procedure and approaches are developed to verify and validate fatigue analysis models and procedure used for the present case study.4).The parametric studies with a set of design variables to show the feasibility and flexibility of using simulation methods to evaluate the influence of multiple design variables on wheel products.