The design and manufacture of products which must perform under load is challenging for engineers and designers. As such products must frequently operate for long operating cycles under continuous weight. Simulations help in designing and testing virtually, to ensure the manufactured product performs in the real world. In this project the final prototype was physically tested on a specially designed rig to evaluate the performance.
The products in this case are crutches designed to give comfort, avoid slips and last longer. Traditional crutches cannot be used on uneven outdoor terrain, there is also risk of slipping on smooth surfaces. To overcome these challenges and provide greater mobility outdoors, the start-up had designed affordable crutches from metal with rubber grips. After a pilot test was conducted the users complained about the lifetime usage of the crutches, which turned out to be lower than estimated. To improve the life and increase the satisfaction of the product the start-up approached Design Alpha. The team at Design Alpha simulated design of the crutches using mechanical dynamic simulation in CAD, with Finite Element Analysis. The theoretical results were very well matching to the current life cycle, which was lower than expectations of the consumers.
To improve the product lifetime usage, Design Alpha carried out redesign using inferences from the simulations. The redesigned prototype provided showed improved reliability. Now, it was time to physically validate the product life using the new physical prototype. A rig of test systems was designed, which simulated the usage for physically testing the reliability of the newly designed crutches. This is like testing a car by putting weights and driving on bad roads to check how well it can perform. The project not only helped to improve the design and increase life. It also resulted in a 35% reduction of the cost. The load carrying capability of the redesigned crutches was enhanced from 80 kg to 130 kg. The reliability factor increased from 4 lakhs operations to 10 lakhs operations. It means a physically disabled person can use crutches with confidence. The applied weight could be as high as 130 kg, it must be noted that while walking a person weighs higher due to the force applied. The redesigned and newly manufactured crutches would be able to work for 10 lakh steps for the user, it outlasts a wooden crutch by manifold.
