JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 64

thermoplastic

Fig. 1: Thermoforming of Thermoplastic Composite Stringers

Figure 1 illustrates the key elements of the stamp forming process, including the matched-metal core and cavity dies about to stamp a heated laminate blank. The key advantages of thermoforming versus other composite fabrication methods include low cycle times (<10 min) and high repeatability. Figure 2 depicts a typical thermoformed and trimmed C-channel stringer and a stringer-stiffened panel assembly into which it gets assembled. Unlike thermoset components, individual thermoplastic components may be assembled into larger structures by re-melting the various components together. The resulting unitized structures thus bypass the requirements for heavy and expensive fasteners required for adhesivebonded assemblies.

Fig. 3: Mechanical Properties of Advanced Thermoplastics vs. Thermosets [1]

Strength limitations of stringers in vertical compression
Basic thermoformed composite stringers are excellent in axial and bending loads, but suboptimal for concentrated vertical or “z-direction” compression loads. As vertical compression loads transfer around the radii of a stringer, the stringer radii typically crush or yield well below the stringer web strength capability and local reinforcement may be required to meet load requirements. Figure 4 illustrates a typical vertical compression loading condition on a stringer-stiffened floor panel. The panel is supported by a substructure at either end, and a vertical load is applied near to one end. The load transfers through the top facesheet, through the stringer upper radius, the web and the lower radius into the lower facesheet before finally being reacted by the substructure.

Fig. 2: Thermoformed C-Channel Stringers in a Stringer-Stiffened Panel

Advanced thermoplastics vs. thermosets
In addition to the producibility advantages described above, thermoplastics offer all the excellent strength and corrosion properties of advanced thermosets but with greater damage tolerance and better hot-wet performance. Figure 3 illustrates the mechanical performance of PEEK (poly-ether-ether-ketone) and PEKK (poly-ether-ketoneketone) versus primary and secondary structure epoxies. Thermoplastic properties are as good if not slightly better than thermosets for open-hole tension (OHT) and openhole compression (OHC), but significantly outperform thermosets in compression after impact (CAI).

Fig. 4: Example of Radius Crushing on a Stringer-Stiffened Floor Panel

When stringers undergo vertical compression loads, radii experience a complex interaction of shear and bending and begin to yield long before the web fails in compression. Stringers begin to yield in interlaminar tension (ILT) on the internal radius or in fibre failure at the facesheet junction along the external radius. Figure 5 depicts the typical radius-crushing failure modes.

64 jec composites magazine / No76 October - November 2012



JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012

Cover
Edito
Point of view: high-perfomance
Contents
COMPANY & BUSINESS In Brief
APPLICATIONS
- Bicycle
- Kayak
- Urban car
MARKET
- Human resources
- Aramid & basalt
SPECIAL JEC AMERICAS
- Floorplan
- 6th I.C.S.
- Academics posters area
- Awards
- Eductation & Skills
- Innovations Report & News
- Moulding
- Injection
- Defense
- CNC
- Land transportation
RESEARCH & DEVELOPMENT
- Thermoplastic
- Tape placement
- Cost effectiveness
TECHNOLOGY & INNOVATIONS
- Out-of-autoclave
- CFRC
- Software
Agenda of Events
Index
In the world
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - Cover
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 2
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - Edito
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - Point of view: high-perfomance
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 5
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - Contents
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 7
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 8
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 9
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - COMPANY & BUSINESS In Brief
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 11
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - Bicycle
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 13
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 14
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - Kayak
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - Urban car
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 17
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 18
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 19
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - Human resources
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 21
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - Aramid & basalt
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 23
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 24
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 25
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 26
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - SPECIAL JEC AMERICAS
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - Floorplan
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 29
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 30
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - 6th I.C.S.
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 32
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 33
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 34
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 35
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - Academics posters area
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 37
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - Awards
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 39
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 40
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 41
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - Eductation & Skills
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 43
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - Innovations Report & News
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 45
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 46
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 47
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 48
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 49
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - Moulding
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 51
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 52
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - Injection
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 54
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 55
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - Defense
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 57
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - CNC
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 59
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - Land transportation
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 61
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 62
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - Thermoplastic
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 64
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 65
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 66
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 67
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 68
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 69
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - Tape placement
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 71
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 72
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 73
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - Cost effectiveness
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 75
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 76
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 77
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 78
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 79
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 80
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - Out-of-autoclave
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 82
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - CFRC
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 84
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 85
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - - Software
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 87
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - Agenda of Events
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - Index
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - In the world
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 91
JEC COMPOSITES MAGAZINE - Issue #76 - October/November 2012 - 92
https://www.nxtbook.fr/newpress/jeccomposites/jcm2211_148
https://www.nxtbook.fr/newpress/jeccomposites/jcm2209_147
https://www.nxtbook.fr/newpress/jeccomposites/jcm2206_146
https://www.nxtbook.fr/newpress/jeccomposites/jcm2204_145
https://www.nxtbook.fr/newpress/jeccomposites/jcm2201_144
https://www.nxtbook.fr/newpress/jeccomposites/jcm211_143
https://www.nxtbook.fr/newpress/jeccomposites/jcm2109_142
https://www.nxtbook.fr/newpress/jeccomposites/jcm2107_141
https://www.nxtbook.fr/newpress/jeccomposites/jcm2105_140
https://www.nxtbook.fr/newpress/jeccomposites/jcm2103_139
https://www.nxtbook.fr/newpress/jeccomposites/jcm-experts-digest-additive-manufacturing-2020
https://www.nxtbook.fr/newpress/jeccomposites/jcm2101_138
https://www.nxtbook.fr/newpress/jeccomposites/jcm2011_Special_Issue4
https://www.nxtbook.fr/newpress/jeccomposites/jcm2011_137
https://www.nxtbook.fr/newpress/jeccomposites/jcm2009_136
https://www.nxtbook.fr/newpress/jeccomposites/jcm2007_135
https://www.nxtbook.fr/newpress/jeccomposites/jcm_2020_Q1_Innovation_Report
https://www.nxtbook.fr/newpress/jeccomposites/jcm2005_Special_Issue3
https://www.nxtbook.fr/newpress/jeccomposites/jcm2005_134
https://www.nxtbook.fr/newpress/jeccomposites/jcm2003_133
https://www.nxtbook.fr/newpress/jeccomposites/jcm2001_132
https://www.nxtbook.fr/newpress/jeccomposites/jcm1911_Special_Issue2
https://www.nxtbook.fr/newpress/jeccomposites/jcm1911_131
https://www.nxtbook.fr/newpress/jeccomposites/jcm1909_130
https://www.nxtbook.fr/newpress/jeccomposites/jcm1907_129
https://www.nxtbook.fr/newpress/jeccomposites/jcm1905_128
https://www.nxtbook.fr/newpress/jeccomposites/jcm1903_Special_Issue1
https://www.nxtbook.fr/newpress/jeccomposites/jcm1903_127
https://www.nxtbook.fr/newpress/jeccomposites/jcm1901_126
https://www.nxtbook.fr/newpress/jeccomposites/jcm1811_125
https://www.nxtbook.fr/newpress/jeccomposites/jcm1810_124
https://www.nxtbook.fr/newpress/jeccomposites/jcm1808_123
https://www.nxtbook.fr/newpress/jeccomposites/jcm1807_122
https://www.nxtbook.fr/newpress/jeccomposites/jcm1805_121
https://www.nxtbook.fr/newpress/jeccomposites/jcm1804_120
https://www.nxtbook.fr/newpress/jeccomposites/jcm1803_119
https://www.nxtbook.fr/newpress/jeccomposites/jcm1802_119-Supplement_Innovation_Report
https://www.nxtbook.fr/newpress/jeccomposites/jcm1801_118
https://www.nxtbook.fr/newpress/jeccomposites/jcm1711_117
https://www.nxtbook.fr/newpress/jeccomposites/jcm1710_116
https://www.nxtbook.fr/newpress/jeccomposites/jcm1708_115
https://www.nxtbook.fr/newpress/jeccomposites/jcm1707_114
https://www.nxtbook.fr/newpress/jeccomposites/jcm1706_113
https://www.nxtbook.fr/newpress/jeccomposites/jcm1704_112
https://www.nxtbook.fr/newpress/jeccomposites/jcm1703_111
https://www.nxtbook.fr/newpress/jeccomposites/jcm1701_110
https://www.nxtbook.fr/newpress/jeccomposites/jcm1611_109
https://www.nxtbook.fr/newpress/jeccomposites/jcm1610_108
https://www.nxtbook.fr/newpress/jeccomposites/jcm1608_107
https://www.nxtbook.fr/newpress/jeccomposites/jcm1607_106
https://www.nxtbook.fr/newpress/jeccomposites/jcm1605_105
https://www.nxtbook.fr/newpress/jeccomposites/jcm1604_104
https://www.nxtbook.fr/newpress/jeccomposites/jcm1603_103
https://www.nxtbook.fr/newpress/jeccomposites/jcm1601_102
https://www.nxtbook.fr/newpress/jeccomposites/jcm1511_101
https://www.nxtbook.fr/newpress/jeccomposites/jcm1510_100
https://www.nxtbook.fr/newpress/jeccomposites/jcm1509_99
https://www.nxtbook.fr/newpress/jeccomposites/jcm1507_98
https://www.nxtbook.fr/newpress/jeccomposites/jcm1505_97
https://www.nxtbook.fr/newpress/jeccomposites/jcm1504_96
https://www.nxtbook.com/newpress/jeccomposites/jcm1503_95
https://www.nxtbook.com/newpress/jeccomposites/jcm1501_94
https://www.nxtbook.com/newpress/jeccomposites/jcm1412_93
https://www.nxtbook.com/newpress/jeccomposites/jcm1410_92
https://www.nxtbook.com/newpress/jeccomposites/jcm1409_91
https://www.nxtbook.com/newpress/jeccomposites/jcm1406_90
https://www.nxtbook.com/newpress/jeccomposites/jcm1405_89
https://www.nxtbook.com/newpress/jeccomposites/jcm1404_88
https://www.nxtbook.com/newpress/jeccomposites/jcm1403_87
https://www.nxtbook.com/newpress/jeccomposites/jcm1401_86
https://www.nxtbook.com/newpress/jeccomposites/jcm1311_85
https://www.nxtbook.com/newpress/jeccomposites/jcm1310_84
https://www.nxtbook.com/newpress/jeccomposites/jcm1308_83
https://www.nxtbook.com/newpress/jeccomposites/jcm1307_82
https://www.nxtbook.com/newpress/jeccomposites/jcm1305_81
https://www.nxtbook.com/newpress/jeccomposites/jcm1304_80
https://www.nxtbook.com/newpress/jeccomposites/jcm1303_79
https://www.nxtbook.com/newpress/jeccomposites/jcm1301_78
https://www.nxtbook.com/newpress/jeccomposites/jcm1212_77
https://www.nxtbook.com/newpress/jeccomposites/jcm1210_76
https://www.nxtbook.com/newpress/jeccomposites/jcm1208_75
https://www.nxtbook.com/newpress/jeccomposites/jcm1207_74
https://www.nxtbook.com/newpress/jeccomposites/jcm1206_73
https://www.nxtbook.com/newpress/jeccomposites/jcm1204_72
https://www.nxtbook.com/newpress/jeccomposites/jcm1203_71
https://www.nxtbook.com/newpress/jeccomposites/jcm1201_70
https://www.nxtbook.com/newpress/jeccomposites/jcm1111_69
https://www.nxtbook.com/newpress/jeccomposites/jcm1110_68
https://www.nxtbook.com/newpress/jeccomposites/jcm1108_67
https://www.nxtbook.com/newpress/jeccomposites/jcm1107_66
https://www.nxtbook.com/newpress/jeccomposites/jcm1105_65
https://www.nxtbook.com/newpress/jeccomposites/jcm1104_64
https://www.nxtbook.com/newpress/jeccomposites/jcm1103_63
https://www.nxtbook.com/newpress/jeccomposites/jcm1101_62
https://www.nxtbook.com/newpress/jeccomposites/jcm1011_61
https://www.nxtbook.com/newpress/jeccomposites/jcm1010_60
https://www.nxtbook.com/newpress/jeccomposites/jcm1009_59
https://www.nxtbook.com/newpress/jeccomposites/jcm1006_58
https://www.nxtbook.com/newpress/jeccomposites/jcm1005_57
https://www.nxtbook.com/newpress/jeccomposites/jcm1004_56
https://www.nxtbook.com/newpress/jeccomposites/jcm1003_55
https://www.nxtbook.com/newpress/jeccomposites/jcm1001_54
https://www.nxtbook.com/newpress/jeccomposites/jcm0911_53
https://www.nxtbook.com/newpress/jeccomposites/jcm0910_52
https://www.nxtbook.com/newpress/jeccomposites/jcm0909_51
https://www.nxtbook.com/newpress/jeccomposites/jcm0907-08_50
https://www.nxtbook.com/newpress/jeccomposites/jcm0906_49
https://www.nxtbook.com/newpress/jeccomposites/jcm0904_48
https://www.nxtbook.com/newpress/jeccomposites/jcm0903_47
https://www.nxtbook.com/newpress/jeccomposites/jcm0901_46
https://www.nxtbook.com/newpress/jeccomposites/jcm0811_45
https://www.nxtbook.com/newpress/jeccomposites/jcm0810_44
https://www.nxtbook.com/newpress/jeccomposites/jcm0809_43
https://www.nxtbook.com/newpress/jeccomposites/jcm0807_42
https://www.nxtbook.com/newpress/jeccomposites/jcm0806_41
https://www.nxtbook.com/newpress/jeccomposites/jcm0805_40
https://www.nxtbook.com/newpress/jeccomposites/jcm0803_39
https://www.nxtbook.com/newpress/jeccomposites/jcm0801_38
https://www.nxtbook.com/newpress/jeccomposites/jcm0712_37
https://www.nxtbook.com/newpress/jeccomposites/jcm0710_36
https://www.nxtbook.com/newpress/jeccomposites/jcm0709_35
https://www.nxtbook.com/newpress/jeccomposites/jcm0707_34
https://www.nxtbook.com/newpress/jeccomposites/jcm0706_33
https://www.nxtbookmedia.com