Structural strength analysis of the adjustment for seat height, leg rest angle, and backrest angle to design a wheelchair

Abstract

A wheelchair is a mobility aid usually designed to improve movement, facilitate daily activities, and enhance the quality of life for individuals with walking difficulties, particularly those with paralysis or elderly individuals. If a wheelchair lacks sufficient features, its functionality can be inadequate, leading to inefficient use and discomfort for the user. Conducting a strength analysis, particularly focusing on stress distribution within the structural design, can aid recommend wheelchair designs that effectively support users in various scenarios. This research aims to perform a strength analysis to inform the design of a wheelchair intended for medical applications. The study examines the effects of variations in seat height (34 cm, 50 cm, and 66 cm), leg rest angle (30 degrees, 60 degrees, and 90 degrees), and backrest angle (30 degrees, 60 degrees, and 90 degrees) on wheelchair design. The details regarding idea design and strength analysis, namely von Mises stress and displacement distributions, of various scenarios are analyzed using three-dimensional finite element wheelchair modeling. The simulation results indicate that the highest maximum von Mises stress observed in all situations does not exceed the material's yield strength. The backrest angle of the 90 degrees' case is found to have a maximum von Mises stress. The study's findings could serve as an appreciated foundation for establishing guidelines for wheelchair design and other medical devices aimed at supporting individuals with disabilities and other kinds of elderly care.