An investigation to determine the physical properties of low pressure molded laminates and their use as structural materials

84 Pages·03.321 MB·English

by  Brown, Kenneth

AN INVESTIGATION TO DETERMINE THE PHYSICAL PROPERTIES
OF1 LOW PRESSURE MOLDED LAMINATES AND THE IK
USE AS STRUCTURAL MATERIALS
A Thesis
Presented to
the Faculty of the School of Engineering
The University of Southern California
In Partial Fulfillment
of the Requirements for the Degree
Master of Science in Mechanical Engineering
*>7
Kenneth Brown
January 1950
UMI Number: EP60493
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This thesis, written by
......... Kenneth_ Brown.............
under the guidance of h.X$... Faculty Committee,
and approved by all its members, has been
presented to and accepted by the Council on
Graduate Study and Research in partial fulfill­
ment of the requirements for the degree of
Master of Science in Mechanical
Engineer ing^..«..Emory___S^..-BQgardus
DEAN
Date...^..t.__
/
n
Faculty Committee
TABLE OP1 CGLTEUTS
CHAPTER PAGE
I. . THE PROBLEMS ARD DEPTHTTIOHS OP5 TERMS USED . . 1
The problem * * ............................ 1
Statement of the p roblem ................. 1
Importance of the study................... 1
Organization of the t h e s i s ............... 2
Definitions of terms used ................... 3
Low pressure molded laminates ............. 3
Polyester resins ......................... 3
Phenolic resins ............................ 4
II. HISTORY OP LAMINATES......................... 5
General characteristics of laminates . . . . 8
General properties ....................... 8
Electrical properties ..................... 9
Thermal properties ....................... 9
Chemical properties ....................... 9
III. THE R E S I N S .................................... 10
Types of r e s i n .............................. 10
Polyester resins ......................... 10
Phenolic resins ........................... 10
Characteristics and selection of polyester
r e s i n s .................................... 11
Discussion of polyester resins .......... 11
Polyester resins available ............... 12
ii
CHAPTER PAGE
Selectron 5003 .............................. 13
Curing characteristics ......... 14
Catalyst . 15
IV. THE RE INF OK C E M E N T .............................. 16
Function and types . . . . . . . . . . . . . . 16
Function . . . . . . . . . . . . . . . . . . 16
Paper reinforcements....................... 16
Cotton fabric reinforcements ............... 17
Fiberglas reinforcements . . . . . . . . . . 17
Selection and weave of reinforcement material 18
Selection.................................. 18
PI ain weave ..................... 18
Long shaft satin weave................... . 18
Uni-directional weave ..................... 21
V. METHODS GP FABRICATION......................... 22
Lay-up impregnation ....................... 24
Hand impregnation .prior to l a y - u p ........ 24
Controlled impregnation prior to lay-up. . . 29
VI. TEST PROCEDURES FOR PHYSICAL PROPERTIES. . . . . 30
Flexural properties of laminates............. 30
Specimen.................................... 30
Experimental procedure ..................... 30
Modulus In flexure......................... 32
Tensile properties of laminates ............. 34
iii
CHAFFER FAGE
Specimen............................. 34
Experimental procedure ................... 34
Compressive properties of laminates . . . . 33
Specimen.................................. 35
Experimental procedure ................... 35
Impact properties of laminates ............. 35
Specimen.................................. 35
Experimental procedure ................... 35
Bearing strength of laminates ............. 37
Specimen.................................. 37
Experimental procedure ................... 37
Shear strength of laminates............... 40
Specimen.................................. 40
Experimental procedure ................... 41
VII. RESULTS OF' THE IB VEST IGAT I C E ................. 43
Effects due to anisotropy................. 43
Effects due to laminate and fabric thickness
variations................................ 45
Stress-strain curves ....................... 45
Edgewise compression properties . ........ 46
Elexural properties......................... 47
Comparison of laminates end aluminum . . . . 47
VIII. SUMMARY AMD CONCLUSION....................... 51
BIBLIOGRAPHY ......................................... 54
iv
CHAPTER PAGE
APPENDIX............................................. 56
LIST OF TABLES
TABLE PAGE
I. Properties of Fiberglas....................... 20
II. Times and Temperatures for Curing Laminates * . 25
III. Ultimate Strengths and Yield Strengths of
Laminates and 24S-T Alclad Alluminum Alloy . . 57
IV. Load Deformation and Stress Headings for
Flexure Tests of Laminates Constructed with
181 Fiberglas................................ 58
V. Load Deformation and Stress Readings for
Tension Tests of Laminates Constructed with
181 Fiberglas . ............................ 59
VI. Load Deformation and Stress Headings for
Compression Tests of Laminates Constructed
with 181 Fiberglas......................... .. 60
VII. Load Deformation and Stress Headings for Edge­
wise Compression Tests of Laminates Con­
structed with 181 Fiberglas................. 61
VIII. Load Deformation and Stress Readings for Shear
Tests of Laminates Constructed with 181
Fiberglas.................................... 62
IX. Load Deformation and Stress Headings for
Bearing Tests of Laminates Constructed
with 181 Fiberglas............................ 63
ii
TABLE PAGE
X, Impact Strength Readings for Laminates
Constructed with 181 Fiberglas................. 64
XI. Modulus in Flexure Values for Laminates
Constructed with 181 Fiberglas................. 64
LIST OF FIGURES
FIGURE . PAGE
1. Chemical Formula of Selectron 5003 ................ 14
2. Types of Fiberglas Leave.......................... 19
3. Vacuum B a g ......................................... 23
4. Lay-up Impregnation................................. 26
5. Hand Impregnation Frior to L a y - u p ............... 27
6. Controlled Impregnation Frior to Lay-up ......... 28
7. Flexure Specimen ................................... 31
b. Baldwin Southwark Universal Testing Machine . . . 33
9. Tension Specimen................................... 36
10. Impact Specimen................................... 36
11. Impact Testing Machine............. 38
12. Bearing Specimen .................................. 39
13. Bearing Test J i g .................................. 39
14. Johnson-type Shear T o o l .......................... 42
15. Stress Deflection Curves for Laminates using 181
Fiberglas...................................... 65
16. Stress Strain and Stress Deflection Curves for
Laminates using 116 Fiberglas ................. 66
17. Stress Strain and Stress Deflection Curves for
Laminates using 162 Fiberglas ................. 67
18. Stress Strain and Stress Deflection Curves for
Laminates using 164 Fiberglas ................. 68