A composite sample of carbon reinforced epoxy has dimensions of in 20 in x 20 in x 0.135 in and mass of 3 lb. The carbon fibres have a modulus of elasticity of 80(106) lb/in2 and a density of 0.15 lb/in3. The epoxy matrix has modulus of elasticity of 0.90(106) lb/in2 and a density of 0.05 lb/in3. Assume there are no voids in the sample, calculate the volume fraction of: (i) The carbon fibres (ii) The epoxy matrix in the sample.

A composite sample of carbon reinforced epoxy has dimensions of in 20 in x 20 in x 0.135 in and mass of 3 lb. The carbon fibres have a modulus of elasticity of 80(106) lb/in2 and a density of 0.15 lb/in3. The epoxy matrix has modulus of elasticity of 0.90(106) lb/in2 and a density of 0.05 lb/in3. Assume there are no voids in the sample, calculate the volume fraction of: (i) The carbon fibres (ii) The epoxy matrix in the sample.

Materials Science And Engineering Properties

1st Edition

ISBN:9781111988609

Author:Charles Gilmore

Publisher:Charles Gilmore

Chapter12: Composite Materials

Section: Chapter Questions

Problem 12.13P

See similar textbooks

Similar questions

In Example Problem 12.1, a uniaxial composite material is made into a circular rod Vbith a 1.27-cm diameter from 70 volume percent continuous carbon fibers and 30 volume percent epoxy. The rod is subject to an axial force of 100,000 N. The composite matcrial in Example Problem 12.1 is to be replaced with a less expensive composite made of 70 volume percent continuous E-glass fibers and 30 volume percent epoxy. The elastic moduli are 5 GPa for the epoxy resin and 72.4 GPa fos the E-glass. (a) Compare the elastic modulus, composite strain, fiber and matrix stresses, and density of this composite with the carbon epoxy composite in Example Problem 12.1. Usc the density of UHM carbon, and assume the density of the epoxy is 1.2g/cm3 . (b) Can both the E-glass fiber and matrix withstand the applied force?
Determine the maximum moment of inertia of the composite figure shown below, in mm^4.
The trimetallic composite section in Figure 4 is compressed by an axial load P = 12 kN applied through a rigid plate. The section consists of a circular steel core surrounded by 2 brass and copper shells. The steel core has a diameter of 10mm, the brass shell has an external diameter of 15mm, and the copper shell has an external diameter of 20mm. The corresponding modulus of elasticity are Ea = 210 GPa, El = 100 GPa and Ec = 120 GPa.(a) Calculate the compressive stress σa, σl, and σc, in the steel, brass, and copper, respectively, that produces the force P.
A steel bar and an aluminum bar are bonded together as shown to form a composite beam. Knowing that the vertical shear in the beam is 4 kips and that the modulus of elasticity is 29 * 106 psi for the steel and 10.6 *106 psi for the aluminum, determine (a) the aver-age shearing stress at the bonded surface, (b) the maximum shearing stress in the beam.
A composite cube with 40-mm sides and the properties shown is made with glass polymer fibers aligned in the x direction. The cube is constrained against deformations in the y and z directions and is subjected to a tensile load of 65 kN in the x direction. Determine (a) the change in the length of the cube in the x direction E = 50 GPa E = 15.2 GPa E = 15.2 GPa P= 0.254 レ、= 0.254 レ、=0.428 %3D The change in the length of the cube in the x direction is mm (up to 4 decimal places please).
A 1500 mm long composite bar consists of aluminum and steel as shown. The cross-sectional area of the aluminum bar is twice that of the steel bar. If the assembly is exposed to an axial tensile load of 250 kN, determine the lengths of each of the components if the elongation of the aluminum is the same with that of the steel. The modulus of elasticity of steel E = 200 GPa and for the aluminum is one-third of the steel.
Two composite bars have the following composition. At an initial temperature of 5 degree C, there is an existing gap of 5mm. Bar 1 and 2 have coefficients of thermal expansion of a1 = 140 X106/°C and a2 = 67 X106/°C, respectively. Determine the temperature at which the 5mm gap is closed. GAP (1) (2) | B C A 540 mm 360 mm 75.20 degrees celsius 55.14 degrees celsius 95.25 degrees celsius 25.06 degrees celsius 50.11 degrees celsius O 5.02 degrees celsius 32.66 degrees celsius
PROBLEM 6.56 50 mm A steel bar and an aluminum bar are bonded together as shown to form a composite beam. Knowing that the vertical shear in the beam is 18 kN and that the modulus of elasticity is 200 GPa for the steel and 73 GPa for the aluminum, determine (a) the average stress at the bonded surface, (b) the maximum stress Aluminum 25 mm Steel in the beam. 36 mm
A composite column is formed by placing a steel bar, 20 mm in diameter and 200 mm long, inside an alloy cylinder of the same length whose internal and external diameters are 20 mm and 25 mm, respectively. The column is then subjected to an axial load of 50 kN. If E for steel is 200 OOO N/mm’ and E for the alloy is 70 000 N/mm’, calculate the stress in the cylinder and in the bar, the shortening of the column and the strain energy stored in the column.
A bar having the cross section shown has been formed by securely bonding brass and aluminum stock. Taking h= 9 mm and using the data given below, determine the largest permissible bending moment when the composite bar is bent about a horizontal axis. Brass Aluminum 30 mm Modulus of elasticity Allowable stress h 30 mm h Aluminum 70 GPa 100 MPa The largest permissible bending moment is Brass 105 GPa 160 MPa 1.17 kN-m.
Write the three functions of the matrix phase in fiber-reinforced composites (FRPs). Briefly state the reason for the need for a strong bond between the fibers and the matrix.
Q2: A composite beam is made of two brass [E =100 GPa] plates bonded to an aluminum [E =75 GPa] bar, as shown in Figure below. The beam is subjected to a bending moment of 1200 N-m acting about the z axis. Determine: (a)the maximum bending stresses in the brass plates and the aluminum bar. (b) the stress in the brass at the joints where the two materials are bonded together.