UCLA Extension

Structural Analysis Techniques for Preliminary Design of Launch Vehicle Structures

Learn the structural analysis methods that identify the most suitable launch vehicle stage structural configuration, constructions, and materials. Lectures emphasize the behavior of structural components as well as TPS designs for reusable vehicles and associated structural design implications. Participants receive structural sizing analysis techniques in over 500 Excel Spread Sheets (example – forward bulkhead sizing uses 9 inputs to define skin thicknesses and actual weight including gage tolerances, welds, etc.)

Over the past 25 years, this Course has been presented to over 600 Engineers at UCLA, 3 NASA Centers (NASA/JSC, NASA/MSFC in 2006 and 2012, NASA/LaRC in 2004 and 2013) , Faculties at OU and MSU, 3 major Aerospace companies (Rockwell, the Boeing Co in 2006, and Northrop/Grumman in 2011). It has been continuously updated to incorporate new NASA Launch Vehicles, the introduction of EXCEL spread sheet technology, advanced manufacturing methods such as Al-Li 2195, spun domes, Friction Stir welding, and Advanced composites. In January 2014 a trade study of Al-Li 2195 vs AS4 and IM7/977-2 Composites, applied to the entire S-II Stage Structure, was included. Special attention is devoted to understanding the behavior of structural components.

Course Program

  • Method of rigid body loads analysis for expendable launch vehicles
  • Existing design details for Saturn S-II Stage, Space Shuttle Orbiter’s external tank, SRMs, and proposed reusable single-stage-to-orbit vehicles to illustrate design details that affect weight and how reusability drives the structure design
  • Thermal protection systems (TPS) and highlights of TPS trade study
  • Structural system optimization derivations for pressurized structures, such as forward, aft, and common bulkheads (domes) for uniform pressure; spherical, cylindrical, ellipsoidal, S-II shape, Cassinian, Torroidal, Ogive, and conical shapes
  • Weight benefits of composites; weight vs. L/d of high-pressure composite metal-lined bottles and optimum method of support
  • Hoop compression loads in bulkheads of specific aspect ratios; how to avoid the compression
  • Structural system optimization derivations for unpressurized shell-stiffened structures; weight optimization of skin/stringers (metallic blade, I, hat sections); honeycomb sandwich; isogrid; square waffle, Orthogrid and AS4 composite hat skin/stringers/frame.
  • Structural system optimization derivations for columns; circular, square, I, T cross-sections
  • Single-stage-to-orbit (SSTO) structure concept and requirements, including 10 Launch loading conditions and on-orbit micrometeoroid and debris impact requirements and shielding implications
  • Composite conical shell structure analysis of Orion command module (CM) support structure and verification NASTRAN analysis

Course Materials

A complete set of approximately 840 quality briefing charts (approximately 600 will be briefed) and an electronic file containing over 500 Excel spreadsheets are provided on the first day of the course. These materials are for participants only and are not otherwise available for sale or unauthorized distribution.

Lecturer

H. Stanley Greenberg, MS, Irvine, California. Mr. Greenberg has 44 years of experience in aerospace structures. From 1996-2006 he was a consultant to Kistler Aerospace, the Boeing Company, and Northrop/Grumman Corporation. He was at Rockwell International’s Space Systems Division (SSD) from 1962-1996. As program manager in 1994 he won 3 major technology development contracts in NASA/MSFC’s NRA program for a single-stage reusable launch vehicle. He directed the study of integrated metallic tank structure/cryogenic insulation/TPS for an AMLS for NASA/LaRC. Mr. Greenberg is recognized by NASA as an expert in structures for launch vehicles. In 1991 he was a candidate for director of large space structures at NASA/LaRC. He managed 3 large space structures technology development contracts for NASA/MSFC culminating in the successful automatic deployment and retraction of a 45-foot long 10-bay truss. He supported the Shuttle Orbiter crew compartment concept development and supervised the structural analysis for its structural design, fabrication, and qualification testing. Prior to the Shuttle program, Mr. Greenberg was involved in optimization studies applied to the structures of the Saturn S-II Stage. Over the past 25 years he has presented this course to over 600 aerospace engineers at UCLA, 3 NAS Centers, Faculties at 2 Engineering Universities, and 3 Major Aerospace Companies

Daily Schedule

Day 1
Morning

Method of Rigid Body Loads Determination for Expendable Launch Vehicles applied to Saturn V Vehicle

  • Prelaunch, max qα, end boost
  • Comparison with actual loads
  • Example of loads prediction for Orion CEV and service module and corroboration
  • Saturn V S-II stage, Space Shuttle Orbiter, ET, and SRM configurations and major design features
  • Space Shuttle assembly at Cape Kennedy
  • RLV, SSTO, Kistler K-1, SLI, Ares, HLLV, and SLS configurations and designs

Afternoon

Highlights of TPS Trade Study

  • 7 candidate TPS/cryo-insulation candidates in 8 vehicle arrangements
  • Selection criteria and process
  • Vehicle surface temperatures and heating rates
  • Tile gap and panel curvature restrictions and recommendations
  • Post-trade study TPS concepts

Pressurized Structures

  • Introduction to pressurized structures
  • Requirements, metallic materials, and weld criteria and inspection

Membrane Theory for Shells of Revolution

  • Derivation of weight-to-volume (W/V) comparison standard, of ellipsoidal, S-II shape, and Cassinian forward bulkheads: uniform pressure
  • Comparison of S-II derived weight with actual S-II
  • Composite implications for tankage and high-pressure metal-lined composite bottle weight vs. L/D and support concept
  • Comparison of ellipsoidal, S-II, and Cassinian bulkhead characteristics
  • Derivation of membrane forces and weight for ellipsoidal forward bulkhead for hydrostatic pressure

Day 3
Morning

Membrane Theory for Shells of Revolution (continued)

  • Derivation of membrane forces and weight for ellipsoidal aft bulkhead for hydrostatic pressure
  • Understanding the hoop compression phenomena for 0.707 aspect ratio
  • Stability analysis to size stiffening for hoop compression and aspect ratios to avoid hoop compression
  • Membrane equations for prolate spheroids, ogives (Shuttle external tank), torroidal and conical shells for uniform pressure
  • Weight to volume (W/V) comparison of 8 studied shapes
  • Support issue for torroidal tanks containing heavy fluids
  • S-II common bulkhead requirements and design: comparison with S-II
  • Weight savings with S-II common bulkhead (CB) compared to separate bulkheads (SB)
  • CB is not always lighter than SB and why
  • Ares I second stage common bulkhead description
  • Discontinuity analysis example at bulkhead to cylinder mating
  • W/V of spherical and cylindrical-nested tanks with pros and cons
  • Proof test as qualification tool and screen for maximum flaw size for life prediction
  • Resulting non-optimum weight additions

Afternoon

Stiffened Shell Structures

  • 8 constructions are presented
  • Equations used in derivation of skin/stringer/frame optimizations
  • Local stability, Euler stability, Johnson interaction, etc.
  • Derivation of blade, I, and hat section skin-stringer optimization analysis applicable to metallic designs
  • Hat section derivation using crippling equations
  • Composite hat section skin/stringer analysis methodology and designs
  • Derivation of tbar for stability frame EI requirement
  • Illustrative examples
  • Skin-stringer-frame optimization examples

Day 3
Morning

Stiffened Shell Structures (continued)

  • Skin-stringer beam column design analysis
  • Optimization of bulkhead aspect ratio through skirt and bulkhead trade
  • 7 S-II stage structure major components weight predictions using developed methods and comparison with actual weight
  • Weight optimization of metal and composite honeycomb sandwich, isogrid, square waffle, and Orthogrid constructions applied to axially loaded cylinders
  • Comparison of t bars for metallic blade, I, and hat skin/stringer/frame designs with metallic and composite honeycomb sandwich, isogrid square waffle, and Orthogrid for wide range of Nx loadings and stage diameters
  • Honeycomb sandwich flat panels and corrugated shear panel optimization
  • Unpressurized structures non-optimum weight additions

Afternoon

Trade Study of Al-Li vs Advanced Composites for entire S-II tage Structure
SSTO Configuration, Design Criteria, Design Requirements
Derivation of Rigid Body loads from Prelaunch to Landing (10 conditions)

  • On-orbit micrometeoroid and debris hazard and required shielding
  • Summary of 10 vehicle loading conditions and illustration of landing loads

Orion Crew Module Composite Conical Shell Support Structure

  • Spreadsheet sizing of longerons, frames, and stringers and NASTRAN verification analysis

Optimization of Columns

  • Round, square, and 4 open sections with illustrative examples
  • Torsional stability of open sections

For more information contact the Short Course Program Office:
shortcourses@uclaextension.edu (310) 825-3344 | fax (310) 206-2815

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