1 / 12

AERSP 301 Torsion of Multi-Cell Cross-Sections

AERSP 301 Torsion of Multi-Cell Cross-Sections. Jose Palacios July 2008. Mid-term Exam Evening Exam July 29, 2:00 pm VLRCOE HW Policy Due in my mail box by end of day on due date Late policy -10 % per day starting with HW 4 Torsion of Multi-Cell sections Ch. 23.3.

india
Télécharger la présentation

AERSP 301 Torsion of Multi-Cell Cross-Sections

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. AERSP 301Torsion of Multi-Cell Cross-Sections Jose Palacios July 2008

  2. Mid-term Exam • Evening Exam • July 29, 2:00 pm VLRCOE • HW Policy • Due in my mail box by end of day on due date • Late policy • -10 % per day starting with HW 4 • Torsion of Multi-Cell sections Ch. 23.3

  3. Pure torsion of multi-cell c/s • Pure torsion case, no axial restraint ( no direct stresses, only shear stresses present). • Wing booms have no effect in the pure torsion case. • Wing section comprises N cells, carries torque T. • All cells experience the same rate of twist.

  4. Pure torsion of multi-cell c/s • Individual torques (unknown) are generated in each cell • Each cell develops constant shear flow:

  5. Pure torsion of multi-cell c/s • Also use compatibility of rate of twist between the cells. • For the Rth cell the rate of twist is: Note: for each wall

  6. Pure torsion of multi-cell c/s Rearranging terms: or

  7. Pure torsion of multi-cell c/s • In general terms: R-1,Ris for wall common to cells R-1 & R Ris for all the walls enclosing the Rth cell R+1,R is for wall common to cells R & R+1

  8. Skin panels and spar webs are frequently made from different materials, so instead of: We use: From which: If , the modulus weighted thickness Then: Pure torsion of multi-cell c/s

  9. Calculate shear stress distribution in the walls of the 3-cell wing section shown when it is subjected to 11.3 kNm anti-clockwise torque. Use GREF = 27600 N/mm2 Multi-Cell Torsion Sample Problem

  10. Multi-Cell Torsion Sample Problem Choosing GREF = 27,600 N/mm then, Similarly: Similarly:

  11. Multi-Cell Torsion Sample Problem For Cell I: 1 For Cell II: 2 For Cell III: 3

  12. Multi-Cell Torsion Sample Problem In addition: (Looking at the torque) 4 Solving equations 1 – 4 simultaneously: 7.3 Pa 5.8 Pa 4.6 Pa qI = 7.1 N/mm 0.89 Pa qII = 8.9 N/mm 2.9 Pa 4.6 Pa qIII = 4.2 N/mm 7.3 Pa 4.6 Pa

More Related