Date of Award

6-2022

Document Type

Thesis

Publisher

Santa Clara : Santa Clara University, 2022.

Department

Mechanical Engineering

First Advisor

Drazen Fabris

Second Advisor

Nikola Djordjevic

Abstract

The goal of the Mars Rover Crash Vehicle Test Article is to act as an impact-absorbing crumple-zone structure that protects a Mars Rover in the case of failure of other landing systems. This crash vehicle was designed for free-fall applications to absorb drops from different heights due to its modular crumple zone system. The design utilized readily available and recycled materials to create a low-cost, quick-build-time, modular system.

The design was split into two subsystems-the Crumple Zone and Inner Vessel-that would be placed inside and around the Outer Frame. The Crumple Zone underwent various iterations with the final design being columns of aluminum cans at the four corners of the Outer Frame. The Inner Vessel consisted of shock absorbers mounted to the sides of the Outer Frame that held the platform on which the Mars Rover would rest.

This scaled down design underwent three drop tests from a height of three meters. The first two tests utilized 144 aluminum cans for a maximum crumpling distance of 40.64 cm. These tests saw very little plastic deformation in the Crumple Zone and a 15 cm bounce after ground-impact, leading to the discovery of unwanted friction within the system. Additionally, the recorded acceleration data only gave a maximum acceleration of 6.28 g’s when 30 were expected due to the accelerometers only recorded at a sampling rate of 14 Hz and not the expected 250 Hz. Because of these errors in these tests, the system and testing procedure were modified for a third test.

The third test saw the system mass increase by 22.6 kg, a Crumple Zone of 72 cans of 20.32 cm maximum crumpling distance, and a maximum sampling rate setting of 1250 Hz. Although only 52 Hz were achieved, the system behaved as expected, and recorded an acceleration of 21.02 g’s, had no rebound, and absorbed 17.73J per can. The successes from this test indicate that scaling up this design is cost-effective and feasible for a Mars Rover with a mass upwards of 1000 kg.

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