Appendixes A.1 WOVEN FABRIC TERMINOLOGY Basic woven fabrics consist of two sets of yarns interlaced at right angles to create a single layer.Such biaxial or 0/90 fabrics are characterized by the following nomenclature: 1.Yarn construction:May include the strand count as well as the number of strands twisted and plied together to make up the yarn.In case of glass fibers,the strand count is given by the yield expressed in yards per pound or in TEX,which is the mass in grams per 1000 m.For example,if the yarn is designated as 150 2/3,its yield is 150 X 100 or 15,000 yd/lb.The 2/after 150 indicates that the strands are first twisted in groups of two, and the/3 indicates that three of these groups are plied together to make up the final yarn.The yarns for carbon-fiber fabrics are called tows.They have little or no twist and are designated by the number of filaments in thousands in the tow.Denier(abbreviated as de)is used for designating Kevlar yarns,where 1 denier is equivalent to 1 g/9000 m of yarn. 2.Count:Number of yarns (ends)per unit width in the warp (lengthwise) and fill (crosswise)directions (Figure A.1.1).For example,a fabric count of 60 X 52 means 60 ends per inch in the warp direction and 52 ends per inch in the fill direction. 3.Weight:Areal weight of the fabric in ounces per square yard or grams per square meter. 4.Thickness:Measured in thousandths of an inch (mil)or in millimeters. 5.Weave style:Specifies the repetitive manner in which the warp and fill yarns are interlaced in the fabric.Common weave styles are shown in Figure A.1.2. (a)Plain weave,in which warp and fill yarns are interlaced over and under each other in an alternating fashion. (b)Basket weave,in which a group of two or more warp yarns are interlaced with a group of two or more fill yarns in an alternating fashion. (c)Satin weave,in which each warp yarn weaves over several fill yarns and under one fill yarn.Common satin weaves are crowfoot satin or four-harness satin,in which each warp yarn weaves over three and under one fill yarn,five-harness satin (over four,under one),and eight-harness satin (over seven,under one). 2007 by Taylor&Francis Group.LLC
Appendixes A.1 WOVEN FABRIC TERMINOLOGY Basic woven fabrics consist of two sets of yarns interlaced at right angles to create a single layer. Such biaxial or 0=90 fabrics are characterized by the following nomenclature: 1. Yarn construction: May include the strand count as well as the number of strands twisted and plied together to make up the yarn. In case of glass fibers, the strand count is given by the yield expressed in yards per pound or in TEX, which is the mass in grams per 1000 m. For example, if the yarn is designated as 150 2=3, its yield is 150 3 100 or 15,000 yd=lb. The 2= after 150 indicates that the strands are first twisted in groups of two, and the =3 indicates that three of these groups are plied together to make up the final yarn. The yarns for carbon-fiber fabrics are called tows. They have little or no twist and are designated by the number of filaments in thousands in the tow. Denier (abbreviated as de) is used for designating Kevlar yarns, where 1 denier is equivalent to 1 g=9000 m of yarn. 2. Count: Number of yarns (ends) per unit width in the warp (lengthwise) and fill (crosswise) directions (Figure A.1.1). For example, a fabric count of 60 3 52 means 60 ends per inch in the warp direction and 52 ends per inch in the fill direction. 3. Weight: Areal weight of the fabric in ounces per square yard or grams per square meter. 4. Thickness: Measured in thousandths of an inch (mil) or in millimeters. 5. Weave style: Specifies the repetitive manner in which the warp and fill yarns are interlaced in the fabric. Common weave styles are shown in Figure A.1.2. (a) Plain weave, in which warp and fill yarns are interlaced over and under each other in an alternating fashion. (b) Basket weave, in which a group of two or more warp yarns are interlaced with a group of two or more fill yarns in an alternating fashion. (c) Satin weave, in which each warp yarn weaves over several fill yarns and under one fill yarn. Common satin weaves are crowfoot satin or four-harness satin, in which each warp yarn weaves over three and under one fill yarn, five-harness satin (over four, under one), and eight-harness satin (over seven, under one). 2007 by Taylor & Francis Group, LLC
Warp FIGURE A.1.1 Warp and fill directions of fabrics. Plain weave fabrics are very popular in wet layup applications due to their fast wet-out and ease of handling.They also provide the least yarn slippage for a given yarn count.Satin weave fabrics are more pliable than plain weave fabrics and conform more easily to contoured mold surfaces. In addition to the biaxial weave described earlier,triaxial (0/60/-60 or 0/45/90)and quadraxial (0/45/90/-45)fabrics are also commercially avail- able.In these fabrics,the yarns at different angles are held in place by tying them with stitch yarns. Common weave styles Plain Crowfoot satin 5 Hamess satin FIGURE A.1.2 Common weave styles.(Courtesy of Hexcel Corporation.With permission.) 2007 by Taylor Francis Group,LLC
Plain weave fabrics are very popular in wet layup applications due to their fast wet-out and ease of handling. They also provide the least yarn slippage for a given yarn count. Satin weave fabrics are more pliable than plain weave fabrics and conform more easily to contoured mold surfaces. In addition to the biaxial weave described earlier, triaxial (0=60=60 or 0=45=90) and quadraxial (0=45=90=45) fabrics are also commercially available. In these fabrics, the yarns at different angles are held in place by tying them with stitch yarns. Warp Fill FIGURE A.1.1 Warp and fill directions of fabrics. Common weave styles Plain Crowfoot satin 5 Harness satin FIGURE A.1.2 Common weave styles. (Courtesy ofHexcel Corporation.With permission.) 2007 by Taylor & Francis Group, LLC
A.2 RESIDUAL STRESSES IN FIBERS AND MATRIX IN A LAMINA DUE TO COOLING [1] The following equations,derived on the basis of a composite cylinder model (Figure A.2.1),can be used to calculate the residual stresses in fibers and matrix in a unidirectional composite lamina developed due to differential thermal shrinkage as it cools down from the high processing temperature to the ambient temperature: =40+) 0m=A2, ==4-》 =4(-》 where =radial distance from the center of the fiber rr =fiber radius Im =matrix radius in the composite cylinder model,which is equal to (ri/ve) m,f =subscripts for matrix and fiber,respectively r,0,z=subscripts for radial,tangential (hoop),and longitudinal directions, respectively. Radial Fiber Matrix FIGURE A.2.1 Cross section of a composite cylinder model. 2007 by Taylor Francis Group.LLC
A.2 RESIDUAL STRESSES IN FIBERS AND MATRIX IN A LAMINA DUE TO COOLING [1] The following equations, derived on the basis of a composite cylinder model (Figure A.2.1), can be used to calculate the residual stresses in fibers and matrix in a unidirectional composite lamina developed due to differential thermal shrinkage as it cools down from the high processing temperature to the ambient temperature: srm ¼ A1 1 r2 m r2 , sum ¼ A1 1 þ r2 m r2 , szm ¼ A2, srf ¼ suf ¼ A1 1 r2 m r2 f , szf ¼ A2 1 r2 m r2 f , where r ¼ radial distance from the center of the fiber rf ¼ fiber radius rm ¼ matrix radius in the composite cylinder model, which is equal to (rf=vf 1 2) m,f ¼ subscripts for matrix and fiber, respectively r,u,z ¼ subscripts for radial, tangential (hoop), and longitudinal directions, respectively. Fiber Matrix rf r m Radial Tangential q FIGURE A.2.1 Cross section of a composite cylinder model. 2007 by Taylor & Francis Group, LLC.
The constants A and 42 are given by the following expressions: [(am-a)△22-(am-a)△12】 A1= △T △11△22-△21△12 T(am-a6)△1l-(am-a)△21 △7 △11△22-△21△12 where a=2+》 Ym+ 1 △2=-EaEa/ △21=- [I-m+ 1-m),(1+vm) EfrVf Em EmVf 1 △2=2Au △T =temperature change,which is negative for cooling E =modulus Poisson's ratio 9 =coefficient of linear thermal expansion volume fraction fl,fr,m=subscripts indicating fiber (longitudinal and radial)and matrix, respectively Figure A.2.2 shows the variation of residual stresses for a carbon fiber-epoxy lamina with ve =0.5.The largest stress in the matrix is the longitudinal stress, 0.2 4=0.5 Longitudinal Hoop 0.1 Fiber Matrix 0 Hoop -0.1 Radial Longitudinal -0.2 0.5 1.0 1.5 rir FIGURE A.2.2 Thermal stresses in the fiber and the matrix as a function of radial distance in a 50 vol%AS carbon fiber-reinforced epoxy matrix.(Adapted from Nairn, J.A.,Polym.Compos.,6,123,1985.) 2007 by Taylor Francis Group,LLC
The constants A1 and A2 are given by the following expressions: A1 ¼ (am af1)D22 (am afr)D12 D11D22 D21D12 DT A2 ¼ (am afr)D11 (am af1)D21 D11D22 D21D12 DT where D11 ¼ 2 nm Em þ nf1 Efl vm vf D12 ¼ vm Eflvf þ 1 Em D21 ¼ (1 nfr)vm Efrvf þ (1 nm) Em þ (1 þ nm) Emvf D22 ¼ 1 2 D11 DT ¼ temperature change, which is negative for cooling E ¼ modulus n ¼ Poisson’s ratio a ¼ coefficient of linear thermal expansion v ¼ volume fraction fl, fr, m ¼ subscripts indicating fiber (longitudinal and radial) and matrix, respectively Figure A.2.2 shows the variation of residual stresses for a carbon fiber–epoxy lamina with vf ¼ 0.5. The largest stress in the matrix is the longitudinal stress, Longitudinal Longitudinal 0.5 0.2 0.1 0 0.1 0.2 1.0 r/rf 1.5 Hoop Hoop Matrix Radial Fiber Stress (MPa) per C vf = 0.5 FIGURE A.2.2 Thermal stresses in the fiber and the matrix as a function of radial distance in a 50 vol% AS carbon fiber-reinforced epoxy matrix. (Adapted from Nairn, J.A., Polym. Compos., 6, 123, 1985.) 2007 by Taylor & Francis Group, LLC.
which is tensile.If it is assumed that the lamina is cured from 177C to 25C, the magnitude of this stress will be 29.3 MPa,which is ~25%of the ultimate strength of the matrix.The hoop stress in the matrix is also tensile,while the radial stress is compressive. REFERENCE 1.J.A.Nairn,Thermoelastic analysis of residual stresses in unidirectional high- performance composites,Polym.Compos.,6:123 (1985). 2007 by Taylor Francis Group.LLC
which is tensile. If it is assumed that the lamina is cured from 1778C to 258C, the magnitude of this stress will be 29.3 MPa, which is ~25% of the ultimate strength of the matrix. The hoop stress in the matrix is also tensile, while the radial stress is compressive. REFERENCE 1. J.A. Nairn, Thermoelastic analysis of residual stresses in unidirectional highperformance composites, Polym. Compos., 6:123 (1985). 2007 by Taylor & Francis Group, LLC
A.3 ALTERNATIVE EQUATIONS FOR THE ELASTIC AND THERMAL PROPERTIES OF A LAMINA Property Chamis [1] Tsai-Hahn [2] Eu Same as Equation 3.36 Same as Equation 3.36 E22 ErEm (Vr+m2vm)ErEm Er-VVi(Er -Em) (EmnVr +722VmEr) GGm G12 (Vr+m2Vm)GrGm Gr-VVE(Gr-Gm) (GmV:+712VmGr) 12 Same as Equation 3.37 Same as Equation 3.37 11 Same as Equation 3.58 a2 an Vi (1-V)(1+Eul) E K陆 Krve+Km(1-vr) Kz ViKr Km (1-)Km+K(K:-Ka) Note:In Tsai-Hahn equations for E22 and Gi2,n22 and n2 are called stress-partitioning parameters.They can be determined by fitting these equations to respective experimental data. Typical values of nz2 and m2 for epoxy matrix composites are: Fiber Type Carbon Glass Kevlar-49 722 0.5 0.516 0.516 12 0.4 0.316 0.4 Thermal conductivity. REFERENCES 1.C.C.Chamis,Simplified composite micromechanics equations for hygral,thermal and mechanical properties,SAMPE Quarterly.15:14(1984). 2.S.M.Tsai and H.T.Hahn,Introduction to Composite Materials,Technomic Publish- ing Co.,Lancaster,PA (1980). 2007 by Taylor Francis Group,LLC
REFERENCES 1. C.C. Chamis, Simplified composite micromechanics equations for hygral, thermal and mechanical properties, SAMPE Quarterly, 15:14 (1984). 2. S.M. Tsai and H.T. Hahn, Introduction to Composite Materials, Technomic Publishing Co., Lancaster, PA (1980). A.3 ALTERNATIVE EQUATIONS FOR THE ELASTIC AND THERMAL PROPERTIES OF A LAMINA Property Chamis [1] Tsai–Hahn [2] E11 Same as Equation 3.36 Same as Equation 3.36 E22 EfEm Ef ffiffiffiffi vf p (Ef Em) (vf þ h22vm)EfEm (Emvf þ h22vmEf) G12 GfGm Gf ffiffiffiffi vf p (Gf Gm) (vf þ h12vm)GfGm (Gmvf þ h12vmGf) n12 Same as Equation 3.37 Same as Equation 3.37 a11 Same as Equation 3.58 a22 afT ffiffiffiffi vf p þ(1 ffiffiffiffi vf p ) 1 þ vfnm Ef E11 am K* 11 Kfvf þ Km(1 vf) K22 (1 ffiffiffiffi vf p )Km þ ffiffiffiffi vf p KfKm Kf ffiffiffiffi vf p (Kf Km) Note: In Tsai–Hahn equations for E22 and G12, h22 and h12 are called stress-partitioning parameters. They can be determined by fitting these equations to respective experimental data. Typical values of h22 and h12 for epoxy matrix composites are: Fiber Type Carbon Glass Kevlar-49 h22 0.5 0.516 0.516 h12 0.4 0.316 0.4 * Thermal conductivity. 2007 by Taylor & Francis Group, LLC.
A.4 HALPIN-TSAI EQUATIONS The Halpin-Tsai equations are simple approximate forms of the generalized self-consistent micromechanics solutions developed by Hill.The modulus val- ues based on these equations agree reasonably well with the experimental values for a variety of reinforcement geometries,including fibers,flakes,and ribbons.A review of their developments is given in Ref.[1]. In the general form,the Halpin-Tsai equations for oriented reinforcements are expressed as p1+5nvr a=1- with n=/pm)-1 (pr/pm)+5 where p =composite property,such as E11,E22,G12,G23,and v23 Pr =reinforcement property,such as Er,Gr,and v Pm=matrix property,such as Em,Gm,and vm =a measure of reinforcement geometry,packing geometry,and loading conditions Vr =reinforcement volume fraction Reliable estimates for the factor are obtained by comparing the Halpin-Tsai equations with the numerical solutions of the micromechanics equations [2-4]. For example, =2+40v10 for Eu. g=2”+40v40 forE22, -(月m +40v10 for G12, where /w,and t are the reinforcement length,width,and thickness,respect- ively.For a circular fiber,/=le and t=w=de,and for a spherical reinforce- ment,/=t=w.The term containing v in the expressions for is relatively small up to v=0.7 and therefore can be neglected.Note that for oriented continuous fiber-reinforced composites,-oo,and substitution of n into the Halpin-Tsai equation for Eu gives the same result as obtained by the rule of mixture. Nielsen [5]proposed the following modification for the Halpin-Tsai equa- tion to include the maximum packing fraction,v*: 2007 by Taylor&Francis Group.LLC
A.4 HALPIN–TSAI EQUATIONS The Halpin–Tsai equations are simple approximate forms of the generalized self-consistent micromechanics solutions developed by Hill. The modulus values based on these equations agree reasonably well with the experimental values for a variety of reinforcement geometries, including fibers, flakes, and ribbons. A review of their developments is given in Ref. [1]. In the general form, the Halpin–Tsai equations for oriented reinforcements are expressed as p pm ¼ 1 þ zhvr 1 hvr with h ¼ (pr=pm) 1 (pr=pm) þ z where p ¼ composite property, such as E11, E22, G12, G23, and n23 pr ¼ reinforcement property, such as Er, Gr, and nr pm ¼ matrix property, such as Em, Gm, and nm z ¼ a measure of reinforcement geometry, packing geometry, and loading conditions vr ¼ reinforcement volume fraction Reliable estimates for the z factor are obtained by comparing the Halpin–Tsai equations with the numerical solutions of the micromechanics equations [2–4]. For example, z ¼ 2 l t þ 40v10 r for E11, z ¼ 2 w t þ 40v10 r for E22, z ¼ w t 1:732 þ 40v10 r for G12, where l, w, and t are the reinforcement length, width, and thickness, respectively. For a circular fiber, l ¼ lf and t ¼ w ¼ df, and for a spherical reinforcement, l ¼ t ¼ w. The term containing vr in the expressions for z is relatively small up to vr ¼ 0.7 and therefore can be neglected. Note that for oriented continuous fiber-reinforced composites, z ! 1, and substitution of h into the Halpin–Tsai equation for E11 gives the same result as obtained by the rule of mixture. Nielsen [5] proposed the following modification for the Halpin–Tsai equation to include the maximum packing fraction, v r : 2007 by Taylor & Francis Group, LLC.
p1+5nv, Pm 1-ndvr whereΦ=I+ V*2 Note that the maximum packing fraction,v:,depends on the reinforcement type as well as the arrangement of reinforcements in the composite.In the case of fibrous reinforcements, 1.v*=0.785 if they are arranged in the square array 2.v*=0.9065 if they are arranged in a hexagonal array 3.v*=0.82 if they are arranged in random close packing REFERENCES 1.J.C.Halpin and J.L.Kardos,The Halpin-Tsai equations:a review,Polym.Eng.Sci, 16:344(1976. 2.J.C.Halpin and S.W.Tsai,Environmental factors in composite materials design, U.S.Air Force Materials Laboratory Report,AFML-TR 67-423,June (1969). 3.J.C.Halpin and R.L.Thomas,Ribbon reinforcement of composites,J.Compos. Mater.,2:488(1968). 4.J.C.Halpin,Primer on Composite Materials:Analysis,Chapter 6,Technomic Pub- lishing Co.,Lancaster,PA (1984). 5.L.E.Nielsen,Mechanical Properties of Polymers and Composites,Vol.2,Marcel Dekker,New York (1974). 2007 by Taylor Francis Group,LLC
p pm ¼ 1 þ zhvr 1 hFvr , where F ¼ 1 þ 1 v r v2 r vr. Note that the maximum packing fraction, v r , depends on the reinforcement type as well as the arrangement of reinforcements in the composite. In the case of fibrous reinforcements, 1. v r ¼ 0.785 if they are arranged in the square array 2. v r ¼ 0.9065 if they are arranged in a hexagonal array 3. v r ¼ 0.82 if they are arranged in random close packing REFERENCES 1. J.C. Halpin and J.L. Kardos, The Halpin–Tsai equations: a review, Polym. Eng. Sci., 16:344 (1976). 2. J.C. Halpin and S.W. Tsai, Environmental factors in composite materials design, U.S. Air Force Materials Laboratory Report, AFML-TR 67-423, June (1969). 3. J.C. Halpin and R.L. Thomas, Ribbon reinforcement of composites, J. Compos. Mater., 2:488 (1968). 4. J.C. Halpin, Primer on Composite Materials: Analysis, Chapter 6, Technomic Publishing Co., Lancaster, PA (1984). 5. L.E. Nielsen, Mechanical Properties of Polymers and Composites, Vol. 2, Marcel Dekker, New York (1974). 2007 by Taylor & Francis Group, LLC.
A.5 TYPICAL MECHANICAL PROPERTIES OF UNIDIRECTIONAL CONTINUOUS FIBER COMPOSITES Boron- AS Carbon- T-300- HMS Carbon- GY-70- Kevlar 49- E-Glass- S-Glass- Property Epoxy Epoxy Epoxy Epoxy Epoxy Epoxy Epoxy Epoxy Density.g/cm3 1.99 1.54 1.55 1.63 1.69 138 1.80 1.82 Tensile properties Strength,MPa(ksi)0 1585(230) 1447.5(210) 1447.5(210) 827(120) 586(85) 1379(200 1103(160) 1214(176) 90° 62.7(9.1) 62.0(9) 44.8(6.5) 86.2(12.5) 41.3(6.0) 28.3(4.1) 96.5(14) Modulus GPa(Msi0° 207(30) 127.518.5) 138(20) 207(30) 276(40) 76(11) 39(5.7) 43(6.3) 90° 19(2.7) 9(1.3) 10(1.5) 13.8(2.0) 8.3(1.2) 5.5(0.8) 4.80.7) Major Poisson's ratio 0.21 0.25 0.21 0.20 0.25 0.34 0.30 Compressive properties Strength,MPa(ksi).0 2481.5(360) 1172(170) 1447.5(210) 620(90) 517(75) 276(40) 620(90) 758(110) Modulus..GPa(Msi.0° 221(32) 110(16) 138(20) 171(25) 262(38) 76(11) 32(4.6) 41(6) Flexural properties Strength,MPa (ksi).0 1551(225) 1792(260) 1034(150) 930(135) 621(90) 1137(165) 1172(170) Modulus,GPa (Msi), 117(17) 138(20) 193(28) 262(38) 76(11) 36.5(5.3) 41.4(6) In-plane shear properties Strength,MPa(ksi) 131(19 60(8.7) 62(9) 72(10.4) 96.5(14) 60(8.7) 83(12) 83(12) Modulus.GPa(Msi) 6.4(0.93) 5.7(0.83) 6.5(0.95) 5.9(0.85) 4.1(0.60) 2.1(0.30) 4.8(0.70) Interlaminar shear strength. 110(16) 96.5(14) 96.5(14) 72(10.5) 52(7.5) 48(7) 69(10) 72(10.5) MPa(ksi)o° Source:From Chamis,C.C.,Hybrid and Metal Matrix Composites,American Institute of Aeronautics and Astronautics,New York,1977.With permission
A.5 TYPICAL MECHANICAL PROPERTIES OF UNIDIRECTIONAL CONTINUOUS FIBER COMPOSITES Property Boron– Epoxy AS Carbon– Epoxy T-300– Epoxy HMS Carbon– Epoxy GY-70– Epoxy Kevlar 49– Epoxy E-Glass– Epoxy S-Glass– Epoxy Density, g=cm3 1.99 1.54 1.55 1.63 1.69 1.38 1.80 1.82 Tensile properties Strength, MPa (ksi) 08 1585 (230) 1447.5 (210) 1447.5 (210) 827 (120) 586 (85) 1379 (200) 1103 (160) 1214 (176) 908 62.7 (9.1) 62.0 (9) 44.8 (6.5) 86.2 (12.5) 41.3 (6.0) 28.3 (4.1) 96.5 (14) — Modulus GPa (Msi) 08 207 (30) 127.5 (18.5) 138 (20) 207 (30) 276 (40) 76 (11) 39 (5.7) 43 (6.3) 908 19 (2.7) 9 (1.3) 10 (1.5) 13.8 (2.0) 8.3 (1.2) 5.5 (0.8) 4.8 (0.7) — Major Poisson’s ratio 0.21 0.25 0.21 0.20 0.25 0.34 0.30 — Compressive properties Strength, MPa (ksi), 08 2481.5 (360) 1172 (170) 1447.5 (210) 620 (90) 517 (75) 276 (40) 620 (90) 758 (110) Modulus, GPa (Msi), 08 221 (32) 110 (16) 138 (20) 171 (25) 262 (38) 76 (11) 32 (4.6) 41 (6) Flexural properties Strength, MPa (ksi), 08 — 1551 (225) 1792 (260) 1034 (150) 930 (135) 621 (90) 1137 (165) 1172 (170) Modulus, GPa (Msi), 08 — 117 (17) 138 (20) 193 (28) 262 (38) 76 (11) 36.5 (5.3) 41.4 (6) In-plane shear properties Strength, MPa (ksi) 131 (19) 60 (8.7) 62 (9) 72 (10.4) 96.5 (14) 60 (8.7) 83 (12) 83 (12) Modulus, GPa (Msi) 6.4 (0.93) 5.7 (0.83) 6.5 (0.95) 5.9 (0.85) 4.1 (0.60) 2.1 (0.30) 4.8 (0.70) — Interlaminar shear strength, MPa (ksi) 08 110 (16) 96.5 (14) 96.5 (14) 72 (10.5) 52 (7.5) 48 (7) 69 (10) 72 (10.5) Source: From Chamis, C.C., Hybrid and Metal Matrix Composites, American Institute of Aeronautics and Astronautics, New York, 1977. With permission. 2007 by Taylor & Francis Group, LLC
A.6 PROPERTIES OF VARIOUS SMC COMPOSITES 2007 by Taylr Francis Group. Property SMC-R25 SMC-R50 SMC-R65 SMC-C20R30 XMC-3 Density.g/cm3 1.83 1.87 1.82 1.81 1.97 Tensile strength.MPa(ksi) 82.4(12) 164(23.8) 227(32.9) 289(L)(41.9) 561(L)(81.4) 84(T)(12.2) 69.9T)(10.1) Tensile modulus.GPa(Msi) 13.2(1.9) 15.8(2.3) 14.8(2.15) 21.4(L)(3.1) 35.7(L)(5.2) 12.4T)(1.8) 12.4T)(1.8) Strain-to-failure (% 1.34 1.73 1.67 1.73(L) 1.66(T) 1.58(L) 1.54T) Poisson's ratio 0.25 0.31 0.26 0.30(LT) 0.31(LT) 0.18TL) 0.12TL) Compressive strength.MPa(ksi) 183(26.5) 225(32.6) 241(35) 306(L)(44.4) 480(LT)(69.6) 166T)(24.1) 160(T)(23.2) Shear strength,MPa(ksi) 79(11.5) 62(9.0) 128(18.6) 85.4(12.4) 91.2(13.2) Shear modulus,GPa(Msi) 4.48(0.65) 5.94(0.86 5.38(0.78) 4.09(0.59) 4.47(0.65 Flexural strength,MPa (ksi) 220(31.9) 314(45.6) 403(58.5) 645(L)(93.6) 973(L)(141.1) 165T)(23.9) 139(T)(20.2) Flexural modulus.GPa(Msi) 14.8(2.15) 14(2.03) 15.7(2.28) 25.7(L)(3.73) 34.1(L)(4.95) 5.9T)(0.86) 6.8(T)(1.0) ILSS.MPa (ksi) 30(4.3 25(3.63) 45(6.53) 41(5.95) 55(7.98) Coefficient of thermal expansion,10-C 23.2 14.8 13.7 11.3(L) 8.7(L) 24.6(T) 28.7(T) Source:From Riegner.D.A.and Sanders.B.A..A characterization study of automotive continuous and random glass fiber composites.Proceedings of the National Technical Conference,Society of Plastics Engineers,1979.With permission. Note:All SMC composites in this table contain E-glass fibers in a thermosetting polyester resin.XMC-3 contains 50%by weight of continuous strands at +7.5 to the longitudinal direction and 25%by weight of 25.4 mm(I in.)long-chopped strands
A.6 PROPERTIES OF VARIOUS SMC COMPOSITES Property SMC-R25 SMC-R50 SMC-R65 SMC-C20R30 XMC-3 Density, g=cm3 1.83 1.87 1.82 1.81 1.97 Tensile strength, MPa (ksi) 82.4 (12) 164 (23.8) 227 (32.9) 289 (L) (41.9) 561 (L) (81.4) 84 (T) (12.2) 69.9 (T) (10.1) Tensile modulus, GPa (Msi) 13.2 (1.9) 15.8 (2.3) 14.8 (2.15) 21.4 (L) (3.1) 35.7 (L) (5.2) 12.4 (T) (1.8) 12.4 (T) (1.8) Strain-to-failure (%) 1.34 1.73 1.67 1.73 (L) 1.66 (T) 1.58 (L) 1.54 (T) Poisson’s ratio 0.25 0.31 0.26 0.30 (LT) 0.31 (LT) 0.18 (TL) 0.12 (TL) Compressive strength, MPa (ksi) 183 (26.5) 225 (32.6) 241 (35) 306 (L) (44.4) 480 (LT) (69.6) 166 (T) (24.1) 160 (T) (23.2) Shear strength, MPa (ksi) 79 (11.5) 62 (9.0) 128 (18.6) 85.4 (12.4) 91.2 (13.2) Shear modulus, GPa (Msi) 4.48 (0.65) 5.94 (0.86) 5.38 (0.78) 4.09 (0.59) 4.47 (0.65) Flexural strength, MPa (ksi) 220 (31.9) 314 (45.6) 403 (58.5) 645 (L) (93.6) 973 (L) (141.1) 165 (T) (23.9) 139 (T) (20.2) Flexural modulus, GPa (Msi) 14.8 (2.15) 14 (2.03) 15.7 (2.28) 25.7 (L) (3.73) 34.1 (L) (4.95) 5.9 (T) (0.86) 6.8 (T) (1.0) ILSS, MPa (ksi) 30 (4.3) 25 (3.63) 45 (6.53) 41 (5.95) 55 (7.98) Coefficient of thermal expansion, 106 =8C 23.2 14.8 13.7 11.3 (L) 8.7 (L) 24.6 (T) 28.7 (T) Source: From Riegner, D.A. and Sanders, B.A., A characterization study of automotive continuous and random glass fiber composites, Proceedings of the National Technical Conference, Society of Plastics Engineers, 1979. With permission. Note: All SMC composites in this table contain E-glass fibers in a thermosetting polyester resin. XMC-3 contains 50% by weight of continuous strands at ±7.58 to the longitudinal direction and 25% by weight of 25.4 mm (1 in.) long-chopped strands. 2007 by Taylor & Francis Group, LLC