1 / 25

AE 440 Structures Discipline Lecture 6

AE 440 Structures Discipline Lecture 6. Eric Loth For AE 440 A/C Lecture. Structures Responsibilities. Determine V-n relationships and establish a V-n diagram Establish and maintain load paths

Faraday
Download Presentation

AE 440 Structures Discipline Lecture 6

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. AE 440Structures Discipline Lecture 6 Eric Loth For AE 440 A/C Lecture

  2. Structures Responsibilities • Determine V-n relationships and establish a V-n diagram • Establish and maintain load paths • Determine component materials (weights and dimensions to configuration) and consider environmental impact of acquisition, production and operations • Determine landing gear configuration • Carry out a detailed structural design of the wing box and wing attachment and structurally design landing gear (weights & dimensions to configuration) • Employ FEM Analysis

  3. Three Primary Structural Loads

  4. Typical Aircraft Loads

  5. Limit Load Factors

  6. V-n Diagram http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgFAR.nsf/MainFrame?OpenFrameSet

  7. Load Paths • How loads are transferred from one structural member to another • Wing skin—torsion and shear stress • Wing ribs—maintain shape and rigidity, transfer loads from skin to spars • Wing spars—bending moments • Fuselage—bulkheads, framers, stringers

  8. Lift Distribution

  9. Spanwise Load Distribution

  10. Typical Wing Box (AE 441)

  11. Major Fuselage Loads • Empennage loads due to trim, maneuvering, turbulence and gusts • Pressure loads due to cabin pressurization • Landing gear loads due to landing impact, taxiing and ground maneuvering • Loads induced by the propulsion installation when the latter is attached to the fuselage

  12. Fuselage Structure

  13. Structural Components • Spars • Ribs • Skin • Beam shear • Beam bending • Torsion Cessna Citation II

  14. Materials • Selection criteria • Strength • Stiffness • Density • Cost • Typical materials • Aluminum • Composites • Steel • Titanium • Mini-UAV materials • Plastic • Balsa • Fiber (cloth)

  15. Stress vs. Strain= Stiffness

  16. Landing Gear Loads • Vertical loads primarily caused by non-zero touchdown rates and taxiing over rough surfaces • Longitudinal loads primarily caused by braking loads and rolling friction loads • Lateral loads primarily caused by ‘crabbed landings,’ cross-wind taxiing and ground turning

  17. Common Landing Gear Configurations

  18. Samples of Structural Results from Previous CDRs

  19. V-n Diagram

  20. Spanwise Lift Distribution

  21. Spanwise Load Distribution

  22. Moment Distribution

  23. Structural Weight and Deflection

  24. Structural Configuration (441 level) I-beam gives good resistance to shear (web) and bending (caps)

  25. Structural Details (441 level)

More Related