Mechanical Design (MECH 3334) - Project 1 – Lander Strut Analysis
Required Steps
Free Body Diagram
Equilibrium Equations
Stress Analysis

d

Determine the Force
and Stress transmitted
through each member
in a landing strut
Four Landing Struts
Given
Martian Gravity
Lander Mass = 5.5 Metric tons
θ=20 deg
φ=60 deg
d=0.25 in
Description: Determine the Forces and Stresses transmitted through the members in a landing
strut.
Application: The landing struts provide stability upon contact with the Martian surface. It is very
important to establish a wide base for a landing craft to avoid tip over at contact due to lateral
forces. An example of tip over at contact is the Space X Falcon 9.
https://www.youtube.com/watch?v=ki_dS0vGmpE
Given:
Martian Gravity
Lander Mass = 5.5 Metric tons
θ = 20 deg
φ = 60 deg
d = 0.25 in
Solid rod
Pin Connections
Expectations:
 Goal: Determine the forces and stresses transmitted through the strut members
 Statics
o Simplify the problem into Free Body Diagrams
o Identify your Known’s and Unknown’s
o Solve the equilibrium equations to determine the reactions.
 Mechanics of Materials
o Solve for the Stress
Grading:
Project Grade = 10% of Final Grade
Project Grade = (Team Grade/10) * (Peer Review Grade/5)*10
Important Dates:
Introduction:
2/7/17
Project Due:
2/23/17
Report Format:
This report will consist of the mathematical solution to the project. The solutions must be well
organized and easy to follow. Titles for each section of the solution and a description of the results
for each section must be included.
Report Structure
1. Knowns/Unknowns: List the given parameters. List the parameters you must find.
2. Free Body Diagram: Draw a neat FBD that includes arrows with arrowheads, dimensions,
and all the parameters needed to solve the problem. (When appropriate).
3. Assumptions: List any assumptions made, and the equations you will need to solve the
problem.
4. Steps: Give necessary details so that people can easily follow your calculations. Answers
without the steps will not be accepted.
5. Equations: label each equation with a number (1), (2), (3), etc.
6. Answer: Include units and box your final answers.
7. Neatness: Disorganized, incomplete, and/or copied work will be penalized.
Important Notes:
The instructor highly recommends that students take advantage of symbolic solving software such
as MathCAD, Mathematica, Matlab, and/or Excel to solve this project. These software allow you to
program the equations such that you only need to change the input variable (for example, the
thickness of the square hollow tube) to recalculate the entire project. I also encourage students to
use tools such as Autodesk force effect, Solidworks Simulation tool, NX FEA, and ANSYS Fea to
verify the solution. Late assignments will not be accepted.