JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 51

higher for the second part.

Numerical model
Simulation of curing process is realized using a simulation tool based on the general Finite Element purpose SYSPLY 11.0, which is a part of SYSWORLD software environment (ESI group product) [8]. A macro-mechanical approach is used to solve the manufacturing problem and to predict distortions and residual stresses. The chosen model is based on two weakly coupled submodels: a thermochemical one and a mechanical one. This type of thermochemical model describes the curing behaviour of the resin. A mechanical viscoelastic model is used to calculate the residual stresses. One of the main difficulties faced when setting up such a numerical model is the number of material parameters that need to be determined in both the rubbery and glassy states. The governing equation of the thermochemical model is: (1) where ρ is the laminate density, Cp its specific heat capacity, Q the heat flux, and q the internal heat generation (latent heat). To complete Eq. 1, constitutive Eqs. 2 - 3 are used to close the thermochemical problem to be solved. The heat flux can be described using Fourier’s heat law: (2) where kij is the thermal conductivity tensor.

chemical shrinkage coefficients, respectively. These are thermodependent as well. The glass transition temperature is defined by DiBenedetto equation. The viscoelastic behaviour of composite materials is typically represented by rheological schemes, where n Maxwell elements are in parallel with m springs. The Maxwell element is used to simulate a boundary condition between the rubbery and the glassy state. It is assumed that the material is stress free in the rubbery state. Boundary conditions The mesh geometry of the composite part corresponds to the L shape used in the experiments (Figure 4 (a)). It consists of 300 eightnode brick elements. Different boundary conditions (thermal and mechanical) have to be applied to simulate the curing process. The cure cycle resulting from the experiment is used as an initial BC representing the process parameters. The resulting temperature values are applied to the nodes of the "TOOL" and "BAG" surfaces of the mesh (Figure 4). The mechanical boundary conditions are changed during simulation in order to simulate an in-mould process and a demoulding process. The in-mould cure is modelled by applying zero degree of freedom to the nodes situated on the skin of

The latent heat is the energy released by the resin during cure: (3)

where q(χ, T) is the latent heat (energy per unit volume), ρr the resin density, Htot the total heat released during cure (energy per unit mass), ∂χ/∂t the chemical reaction rate, or cure kinetics, and Vf the fibre volume fraction.

Along this thermochemical model, a mechanical phenomenological-like model proposed earlier by Svanberg [6] is used in a second step. This model only captures the main features of the reaction kinetics. The constitutive equation for an anisotropic linear viscoelastic material is usually written as: (4)

where σij are the stress components, the relaxation moduli, and the total strain and the free thermochemical strain, respectively (i, j, k, l = 1, 2, 3).

The expansion strain consists of a thermal and a chemical component , which depend on the thermal expansion and

No67 August - September 2011 / jec composites magazine
Fig.4: (a) Part dimensions in [mm]; (b) mechanical boundary conditions created to observe only the displacements of the upper side of the Lshaped part, representing the simulation of the demoulding process

51

Research & development



JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011

Cover
Edito
Point of view: "I have a very positive view of the market" by Thomas Hedger
Contents
Agenda of Events
COMPANY & BUSINESS
- In Brief
- Automotive
APPLICATIONS
- Aeronautics
- Building & construction
- Sustainability
MARKET
- Composites
- Asia-Pacific
- Resin
-Productivity
-Human Resources
FEATURE MARINE
- Natural Fibre
- Environment
- Race boat
- Simulation
- Coating
- Bonding
RESEARCH & DEVELOPMENT
- Simulation
- Natural Fibre
TECHNOLOGY & INNOVATIONS
- RTM-S
-Software
- SMC
Index
In the world
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - Cover
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 2
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - Edito
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - Point of view: "I have a very positive view of the market" by Thomas Hedger
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 5
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - Contents
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 7
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 8
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - Agenda of Events
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - PubJEC
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - PubESI
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - - In Brief
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - - Automotive
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - - Aeronautics
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 13
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - - Building & construction
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 15
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 16
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 17
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - - Sustainability
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - - Composites
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 20
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 21
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - - Asia-Pacific
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 23
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 24
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - - Resin
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 26
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 27
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - -Productivity
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 29
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 30
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - -Human Resources
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 32
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - - Natural Fibre
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 34
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - - Environment
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 36
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 37
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - - Race boat
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 39
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - - Simulation
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 41
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - - Coating
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 43
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 44
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 45
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 46
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - - Bonding
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 48
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - - Simulation
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 50
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 51
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 52
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - - Natural Fibre
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 54
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 55
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - - RTM-S
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 57
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 58
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 59
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - -Software
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 61
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 62
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 63
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - - SMC
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - Index
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - In the world
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 67
JEC COMPOSITES MAGAZINE - Issue #67 - August/September 2011 - 68
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