High Energy Wide Area Blunt Impact on Composite Aircraft Structures

279 Pages·2013·58.2 MB·English

UC San Diego
UC San Diego Electronic Theses and Dissertations
Title
High Energy Wide Area Blunt Impact on Composite Aircraft Structures /
Permalink
https://escholarship.org/uc/item/7fq9827j
Author
DeFrancisci, Gabriela K.
Publication Date
2013

Peer reviewed|Thesis/dissertation
eScholarship.org Powered by the California Digital Library
University of California
UNIVERSITY OF CALIFORNIA, SAN DIEGO
High Energy Wide Area Blunt Impact on Composite Aircraft
Structures
A dissertation submitted in partial satisfaction of the
requirements for the degree
Doctor of Philosophy
in
Structural Engineering
by
Gabriela K. DeFrancisci
Committee in charge:
Professor Hyonny Kim, Chair
Professor Chiara Bisagni
Professor Francesco Lanza Di Scalea
Professor Vlado A. Lubarda
Professor Vitali F. Nesterenko
2013
Copyright
Gabriela K. DeFrancisci, 2013
All rights reserved.
The dissertation of Gabriela K. DeFrancisci is approved,
and it is acceptable in quality and form for publication
on microfilm and electronically:
Chair
University of California, San Diego
2013
iii
DEDICATION
My family: Sheilah, Christina, Steven and Laura.
iv
TABLE OF CONTENTS
Signature Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
Dedication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv
Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii
List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiv
List of Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvi
Vita and Publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii
Abstract of the Dissertation . . . . . . . . . . . . . . . . . . . . . . . . . . . xx
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.3 Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.4 Novel Contributions . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.1 High Velocity Versus Low Velocity Impacts . . . . . . . . . . . . . . 12
2.2 Quasi-Static Equivalence . . . . . . . . . . . . . . . . . . . . . . . . 14
2.3 Typical Low Velocity Experimental Setup . . . . . . . . . . . . . . 15
2.4 Impactor Geometry and Material . . . . . . . . . . . . . . . . . . . 17
2.4.1 Impactor Bluntness Effects . . . . . . . . . . . . . . . . . . . 17
2.4.2 Rubber Material Modeling . . . . . . . . . . . . . . . . . . . 18
2.5 Panel Size and Scaling Effects . . . . . . . . . . . . . . . . . . . . . 19
2.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
3 Large Scale Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.2 Blunt Impact Threat Characterization . . . . . . . . . . . . . . . . 22
3.3 Panel Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.3.1 Composite Material . . . . . . . . . . . . . . . . . . . . . . 35
3.3.2 Manufacturing . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.4 Stringer Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3.4.1 Test Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
v
3.4.2 Procedure for Test . . . . . . . . . . . . . . . . . . . . . . . 47
3.4.3 Stringer00 Results . . . . . . . . . . . . . . . . . . . . . . . 47
3.4.4 Stringer01 Results . . . . . . . . . . . . . . . . . . . . . . . 52
3.4.5 Stringer02 Results . . . . . . . . . . . . . . . . . . . . . . . 54
3.4.6 StringerXX Discussion . . . . . . . . . . . . . . . . . . . . . 59
3.5 Phase I Frame Panels . . . . . . . . . . . . . . . . . . . . . . . . . . 60
3.5.1 Representation of Boundary Conditions . . . . . . . . . . . . 61
3.5.2 Phase I FrameXX Test Setup . . . . . . . . . . . . . . . . . 67
3.5.3 Procedure for Test . . . . . . . . . . . . . . . . . . . . . . . 68
3.5.4 Frame01 Results . . . . . . . . . . . . . . . . . . . . . . . . 69
3.5.5 Frame02 Results . . . . . . . . . . . . . . . . . . . . . . . . 77
3.5.6 Phase I FrameXX Discussion . . . . . . . . . . . . . . . . . 83
3.6 Phase II Frame Panels . . . . . . . . . . . . . . . . . . . . . . . . . 85
3.6.1 Test Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
3.6.2 Frame03 Results . . . . . . . . . . . . . . . . . . . . . . . . 88
3.6.3 Frame04-1 Results . . . . . . . . . . . . . . . . . . . . . . . 96
3.6.4 Frame04-2 Results . . . . . . . . . . . . . . . . . . . . . . . 100
3.6.5 Frame by Frame Comparison of Quasi-Static and Dynamic
Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
3.6.6 Energy Quantification . . . . . . . . . . . . . . . . . . . . . 109
3.7 Experimental Conclusions . . . . . . . . . . . . . . . . . . . . . . . 110
4 Modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
4.1 Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
4.1.1 Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
4.1.2 Script Based Model Definition . . . . . . . . . . . . . . . . . 116
4.2 Model Description and Definitions . . . . . . . . . . . . . . . . . . . 118
4.2.1 Rubber Bumper Modeling . . . . . . . . . . . . . . . . . . . 119
4.2.2 Panel Description . . . . . . . . . . . . . . . . . . . . . . . . 120
4.2.3 Effective Fastener Modeling . . . . . . . . . . . . . . . . . . 127
4.3 Mesh Sensitivity Study . . . . . . . . . . . . . . . . . . . . . . . . . 133
4.4 Finite Element Analysis Validation . . . . . . . . . . . . . . . . . . 138
4.5 Panel Geometry and Material Parameter Effects Studies . . . . . . 152
4.5.1 Contribution of Non-Loaded Frames to Overall Stiffness . . 154
4.5.2 Bumper Material Stiffness Study . . . . . . . . . . . . . . . 161
4.5.3 Relative Component Stiffness Study . . . . . . . . . . . . . . 165
4.5.4 Component Material Study . . . . . . . . . . . . . . . . . . 172
4.5.5 Panel Geometry and Material Parameter Study Discussion . 185
4.6 Modeling Methodology Summary . . . . . . . . . . . . . . . . . . . 186
4.7 FEA Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
vi
5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190
5.1 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190
5.2 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
5.3 Future Research Directions . . . . . . . . . . . . . . . . . . . . . . . 194
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
A Cohesive Surfaces/Composites in Abaqus Tutorial . . . . . . . . . . . . . 201
A.1 Failure Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
A.1.1 Cohesive Surfaces . . . . . . . . . . . . . . . . . . . . . . . . 202
A.2 Defining a Composite Laminate Material Orientation . . . . . . . . 206
A.3 Mesh Stack Direction and Element Type . . . . . . . . . . . . . . . 208
A.3.1 Mesh Stack Direction . . . . . . . . . . . . . . . . . . . . . . 208
A.3.2 Mesh Element Type . . . . . . . . . . . . . . . . . . . . . . 210
B Test Fixtures and Boundary Conditions . . . . . . . . . . . . . . . . . . 211
B.1 StringerXX Test Fixtures . . . . . . . . . . . . . . . . . . . . . . . . 211
B.2 Phase I FrameXX Boundary Conditions . . . . . . . . . . . . . . . 215
B.3 Phase II FrameXX Additional Aluminum Frame Boundary Conditions230
B.4 C-Frame Outer Mold Line Tool . . . . . . . . . . . . . . . . . . . . 237
B.5 Shear Tie Outer Mold Line Tool . . . . . . . . . . . . . . . . . . . . 239
B.6 Stringer Silicone Mold . . . . . . . . . . . . . . . . . . . . . . . . . 240
B.7 Phase II Skin Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
vii
LIST OF FIGURES
Figure 1.1.1:Aircraft Surrounded by GSE Between Flights . . . . . . . . . . 2
Figure 1.1.2:Schematic Diagram of Design Load Levels Versus Categories of
Damage Severity as Defined by the FAA [5] . . . . . . . . . . . 3
Figure 1.1.3:Patch Away from Door Indicating Accidental Damage . . . . . 5
Figure 1.1.4:Cylindrical Bumper Typically Found on GSE . . . . . . . . . . 6
Figure 1.1.5:Monolithic Composite Structure . . . . . . . . . . . . . . . . . 6
Figure 1.3.1:Building Block Approach to Understanding Damage to Mono-
lithic Composite Structures . . . . . . . . . . . . . . . . . . . . 8
Figure 1.4.1:High Amount of Skin Deformation in Panel With a Soft Impactor 11
Figure 2.1.1:ComparisonBetween(a)LargeMassand(b)SmallMassImpact
Response [8] . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Figure 2.2.1:Force-DeflectionHistoriesforConcaveShellSpecimenImpacted
at 3.1 m/s and Tested Quasi-Statically [23] . . . . . . . . . . . 15
Figure 2.4.1:High Deformation of Rubber Material During Impact on an
Aluminum Plate [31] . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 3.2.1:Patches Surrounding Door on Boeing 747 . . . . . . . . . . . . 24
Figure 3.2.2:Boeing 737 and Surrounding GSE Between Flights . . . . . . . 24
Figure 3.2.3:Velocity of a Belt Loader Approaching a Boeing 757 Aircraft . . 25
Figure 3.2.4:Difficult Approach Angle of Belt Loader . . . . . . . . . . . . . 26
Figure 3.2.5:Potential Scraping on Fairing as Bumper is Raised to Door Level 27
Figure 3.2.6:Rolling Staircase Contacting Aircraft at an Angle . . . . . . . . 28
Figure 3.2.7:Cylindrical Bumper and “D” Shaped Bumper . . . . . . . . . . 29
Figure 3.2.8:CylindricalBumperand“D” ShapedBumperUsedinExperiments 30
Figure 3.3.1:Composite Fuselage and Acreage Internal Structure [40, 41] . . 31
Figure 3.3.2:Typical StringerXX and FrameXX Test Panels . . . . . . . . . 32
Figure 3.3.3:Shear Tie and Frame Cross Section Dimensions (all units in mm) 33
Figure 3.3.4:Shear Tie Dimensions . . . . . . . . . . . . . . . . . . . . . . . 34
Figure 3.3.5:Stringer Dimensions (all units are in mm) . . . . . . . . . . . . 34
Figure 3.3.6:Frame Side View with Material Orientation for Shear Ties and
Frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Figure 3.3.7:1.8 m Diameter Autoclave at San Diego Composites . . . . . . 37
Figure 3.3.8:Manufacturing Cure Cycle . . . . . . . . . . . . . . . . . . . . 38
Figure 3.3.9:Stringer and Skin Material Orientation . . . . . . . . . . . . . . 38
Figure3.3.10:Skin Outer Mold Line (OML) Tool . . . . . . . . . . . . . . . . 39
Figure3.3.11:Stringer Inner Mold Line (IML) Tool . . . . . . . . . . . . . . . 40
Figure3.3.12:Corner Detail of Stringer-Skin Connection . . . . . . . . . . . . 41
Figure3.3.13:Frame (OML) Tool . . . . . . . . . . . . . . . . . . . . . . . . . 42
Figure3.3.14:Shear Tie (OML) Tool . . . . . . . . . . . . . . . . . . . . . . . 43
Figure 3.4.1:Stringer Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
viii
Figure 3.4.2:Stringer Impact Locations . . . . . . . . . . . . . . . . . . . . . 45
Figure 3.4.3:Rigid76.2mmRadiusIndentor(left)andOEMRubberBumper
(right) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Figure 3.4.4:Panel Stringer02 Test Setup in SATEC Machine . . . . . . . . . 46
Figure 3.4.5:Stringer Test Fixtures (Indentation Location 2, Dimensions are
mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Figure 3.4.6:Stringer00 Force vs. Indentation Curves . . . . . . . . . . . . . 48
Figure 3.4.7:Localized Deformation of Panel Caused by 76.2 mm Radius
Rigid Indentor During First Loading of Stringer00. . . . . . . . 49
Figure 3.4.8:NoVisiblePermanentDeformationAfterFirstLoadingofStringer00
Despite Formation of Delamination . . . . . . . . . . . . . . . . 49
Figure 3.4.9:Stringer00 Peanut Shaped Delamination After First Loading . . 50
Figure3.4.10:Stringer00 After Final Failure Following Second Loading . . . . 51
Figure3.4.11:Stringer00 After Final Failure Following Second Loading; Panel
ReboundedtoOriginalOverallShapeDespitePenetrationDam-
age . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Figure3.4.12:Stringer01 Final Failure Following Fourth Loading, Penetration
of Indentor Through Skin . . . . . . . . . . . . . . . . . . . . . 52
Figure3.4.13:Stringer01 Force vs. Indentation Curves . . . . . . . . . . . . . 53
Figure3.4.14:Deformation of Highly Compliant Rubber Bumper Indentor . . 55
Figure3.4.15:Stringer02 Force vs. Indentation Curves . . . . . . . . . . . . . 56
Figure3.4.16:Stringer02 Delamination Schematic . . . . . . . . . . . . . . . . 57
Figure3.4.17:Stringer02 Delamination Between the Skin and Stringer Follow-
ing Fourth Loading . . . . . . . . . . . . . . . . . . . . . . . . . 58
Figure3.4.18:Stringer02 Following Fifth Loading. Complete Delamination of
the Right-Side Stringer (S2) Out to the Free Edge was Observed 59
Figure 3.5.1:Phase I Test Panel Design Concept . . . . . . . . . . . . . . . . 61
Figure 3.5.2:Deformation State Dependent on Boundary Conditions . . . . . 62
Figure 3.5.3:Hoop and Rotations Degree of Freedom Stiffness at Boundaries 63
Figure 3.5.4:Full Barrel Quarter Symmetric Model with Equivalent Elastic
Constants, 76.2 mm Radius Indentor; Model Represents a Full
Barrel With Fixed Outer Boundaries – Only ¼ of Geometry is
Modeled Due to Quarter Symmetry . . . . . . . . . . . . . . . . 64
Figure 3.5.5:Comparison Metrics Between the Full Barrel Model and Frame
Panel Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Figure 3.5.6:Hoop Displacement for Various Rotational and Translational
Stiffness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Figure 3.5.7:Boundary Rotation for Various Rotational and Translational
Stiffness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Figure 3.5.8:Phase I Frame Panel Experimental Setup . . . . . . . . . . . . 68
Figure 3.5.9:Frame01 Loading History . . . . . . . . . . . . . . . . . . . . . 70
Figure3.5.10:Frame01 Component Locations . . . . . . . . . . . . . . . . . . 71
Figure3.5.11:Frame01 During Loading L3 at 44.48 kN . . . . . . . . . . . . . 72
ix