Can someone please help me with this problem?
In order to reduce the material cost, an engineer decides to use a hybrid beam instead of an all-carbon fiber beam. Both beams have the same overall dimensions with rectangular cross-sections. The hybrid beam contains carbon fibers in the outer layers and S-glass in the core. Costs of the materials are as follows:
Carbon/Epoxy: $ 25/lb
S-glass/Epoxy: $3.00/lb
The densities of carbon/epoxy and S-glass/epoxy composites are 1.70 g/cm3 (0.061 lb/in3) and 2.00 g/cm3 (0.072 lb/in3) respectively. The total carbon fiber thickness in the hybrid beam is equal to the core thickness. Compare the percentage weight penalty and cost savings for the hybrid beam over an all-carbon fiber beam. Do you expect the all-carbon and hybrid beams to have the same bending stiffness? If the answer is “no”, what can be done to make the two stiffness equal?
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