Personal rain protection device for pedestrian

Abstract

At present, the umbrella has established itself as a primary rain protection device and used by all as general everyday item. However, despite years of evolution and being widely accepted, the classic umbrella design still suffers from several design flaws. Hence, the objective of the present study is to design a new rain protection design for pedestrian which can possibly maintain the attractive features and address the shortcomings of classic umbrella. Areas for improvement in classic umbrella are identified through literatures review and interviews from users. Five users were interviewed and their feedback is analyzed to produce a User Persona. Based on the findings from literatures and interviews, a Product Design Specification (PDS) is established with over 16 design requirements defined ranging from Performance, Maintenance, Safety and so forth. Four concept designs are developed with respect to the PDS and based on the Scoring Matrix, Concept 1 (which scores the highest) is selected. Detailed design is performed based on Concept 1 where the each component are modeled in detail using CAD software and their dimensions, materials and weights are defined accordingly. Design for Manufacturing Analysis (DFMA) – Functional Analysis is performed with the established detail design and the design efficiency is computed to be 50 percent. Failure Mode Effect Analysis (FMEA) is performed and sleeve misalignment has been identified as the prominent potential cause of failure with highest Risk Priority Number (RPN). Finite Element Analysis (FEA) has been performed using ABAQUS software package in terms of structural analysis and two conditions were analyzed i.e. Extreme Condition (Heavy rain and strong wind) and Moderate Condition (moderate rain and wind). Based on the displacement result, it can be seen that design is experiencing large deflection i.e. 94cm at extreme condition which makes the design not practical in extreme condition. Consequently, the internal loads are extracted only for moderate conditions and the stress check result (based on manual calculation using MathCAD software package) indicates that the design can withstand the loads satisfactorily.