Overview
During this project we had to design and test a frame assembly for a motor mount structure for a Lycoming O-300. A Firewall was the grounded part that the frame was attached to while the frame had seven attachment points locked to the firewall. This mount must support a 250 LB Lycoming O-300 engine and will undergo two tests; A -3G load of 250LB and a +6G load of the same 250LB load. The structures will be 1 1/2 in ASNI pipe and they have to have seven constraints, being mitered and trimmed were necessary. Lastly, we must pick a material appropriate for the needs of the frame to properly support the engine.
Procedure
Before we completed this overall project we had to complete two tutorials on inventor so we had the knowledge to complete this project. Our first tutorial showed us how to create and modify beams in the Inventor software, showing us how to trim beams to a plane and miter two or more ends of a beam at a joint. The second tutorial we did showed us how to place loads and constraints on different parts of a frame, and then how to simulate those loads on the frame with different materials. Even before going through the two Inventor tutorials, we did an investigation of different materials, an activity that showed us the different properties a material can have as well as what materials are better for different situations, giving us the knowledge we would need to select an appropriate material for our frame.
First we downloaded the file and added the frame by using the design tab. We also had to trim the beams so it met flush with the fire wall, and once all beams were trimmed and mitered correctly, we added constraints to every attachment point. When testing we changed the direction of gravity and applied our two specified loads to the frame within a simulation.
Calculations are below:
First we downloaded the file and added the frame by using the design tab. We also had to trim the beams so it met flush with the fire wall, and once all beams were trimmed and mitered correctly, we added constraints to every attachment point. When testing we changed the direction of gravity and applied our two specified loads to the frame within a simulation.
Calculations are below:
Solution
We concluded at the time that Mild Steel would be the best available material to use (Although, upon later research, this was deemed not the case. Mild steel has a bad tensile strength compared to its other forms and can become easily magnetized). The reason we chose mild steel was partially because I recalled that steel, in general was strong and heat while compromising for high weight. This was true, however we were not aware that Mild Steel, is steel without much alloy content, and low carbon content, essentially stripping the material of the heat resistant quality we desired. To say the least, we did not pick an appropriate material to hold an engine which would reach great temperatures and stress the frame in the process.
The photo to the right shows the visual results of the simulated loads on our engine mount frame. This is showing a force of negative 3Gs being applied to the frame with a load of 250lbs per attachment point. A test of positive 6Gs was also run on this frame, deforming the beams downwards instead of up, and with greater deflection because of the increased force, though the photo of this simulation could not be extracted upon completion. To be technical, our frame did meet all constraints since heat resistance was not a required factor, but it is obvious that, in a real world scenario, the frame would not hold up due to the effects of heat on Mild Steel. Our frame could hold the loads of 250LBs in different directions and at the two specified magnitudes with little deflection and no structural failures. The frame was also assembled to be fixed to the firewall with fixed constraints as was specified in the instructions. |
Conclusion
Questions:
What did we learn?
Both Branden and myself learned how to assign loads to, constrain, create, modify, and simulate beams in Inventor.
What were the roles of your team?
My task was to handle all things related to inventor, including but not limited to; creating the beam, constraining the beam, assigning loads, mitering and trimming, and simulating the beam properly, though I failed to extract one of the pictures of a test I performed. Branden's task was to design the Weebly, which we both thought was equivalent to half the project. Once he typed out everything, I would copy it to my own Weebly and modify some of his text to my own liking. I would say that he played a very important role in the project, and really took a bullet for me considering how much I dislike doing Weebly's. He did his job effectively and produced a nice Weebly.
Is this method of frame generation effective for aerospace engineers?
I would say yes, this is extremely effective for any type of engineer, as long as the results are accurate to real life when the software is used correctly. This is because it allows an engineer to think up and design a frame and test it to see its weaknesses with different materials without having to build or test a time consuming, and possibly costly prototype in real life.
What did we learn?
Both Branden and myself learned how to assign loads to, constrain, create, modify, and simulate beams in Inventor.
What were the roles of your team?
My task was to handle all things related to inventor, including but not limited to; creating the beam, constraining the beam, assigning loads, mitering and trimming, and simulating the beam properly, though I failed to extract one of the pictures of a test I performed. Branden's task was to design the Weebly, which we both thought was equivalent to half the project. Once he typed out everything, I would copy it to my own Weebly and modify some of his text to my own liking. I would say that he played a very important role in the project, and really took a bullet for me considering how much I dislike doing Weebly's. He did his job effectively and produced a nice Weebly.
Is this method of frame generation effective for aerospace engineers?
I would say yes, this is extremely effective for any type of engineer, as long as the results are accurate to real life when the software is used correctly. This is because it allows an engineer to think up and design a frame and test it to see its weaknesses with different materials without having to build or test a time consuming, and possibly costly prototype in real life.