Overview
Frame construction is used throughout the aerospace industry in the creation of welded steel-tube fuselages, piston-engine motor mounts, ribs, and landing gear. In this activity I design a frame assembly for a motor mount structure for a Lycoming O-300 to be installed in a light aircraft.
Equipment
Computer with Autodesk® Inventor® installed and access to the internet.
Procedure
The frame must meet the constraints shown below.
- The large plate represents the aircraft firewall as shown in the image below. This must be grounded as the stable part of the frame. Use fixed constraints on the seven firewall to structural member attachment point.
- The structure will support one Lycoming O-300 engine (250 lb) attached at the three points indicated.
- The structure will be loaded with negative 3 G and positive 6 G which is simulated by exaggerated engine weight.
- The structural members will be 1 ½ in. ANSI pipe.
I calculated the forces that must be simulated with the positive and negative G loads. I labeled the frames below with the forces that will be modeled for each loading condition. I also labeled the structural members below as compression or tension. I predict where the critical point will be for each loading condition.
Design
I used Autodesk Inventor to create a model of your frame design.
Frame Analysis
Negative 3 G
Positive 6 G
Weight and cost of materials needed to produce the frame design
Recorded from http://www.metalsdepot.com/