1000 Stiffness versus WC-Co Diamond Engineering Density2 Be Aluminas Mo W alloys alloys Si Sialons BeO Nialloys CFRP 100 Cu alloys Ti alloys KFRP Zn alloys GFRP alloys Tin Engineering CFRP Rock.stone composites Cement,concrete alloys (m/s) aminate GERP KFRP Lead Mg Porous alloys sh 10 Oak alloys ceramics Pin 10 Engineering r alloys Parallel MEL lo grain PC Balsa Wood Epoxies products PMMA PVC Woods Nylon 3×103 Engineering Pp Polyesters polymers 1.0 Lower Elimit for true solids .Pine F HDPE Perpendicular Guidelines for minimum to grain weight design Spruce PTFE E =C LDPE Balsa Plasticized PVC 0.1 Polymers. Elastomers foams 3×102 E =C Cork Polymers G=3E/8:K=E) foams 0 =C 0.0 100 300 1000 3000 10000 30000 Density.p.kg/m3 Figure 3.17 Modulus of elasticity plotted against density.The heavy envelopes enclose data for a given class of material.The diagonal contours show the longitudinal wave velocity.The guidelines of constant E/p,E12/p,and E/3/p allow selection of materials for minimum-weight,deflection-limited design.[M.F.Ashby,Materials Selection in Mechanical Design,Pergamon Press,1992.]ME 350 14 Stiffness versus Density2