18 APPLICATIONS 18.1 LEVEL 1 18.1.1 Simply Supported Sandwich Beam Problem Statement: 1.The following figure represents a beam made of duralumin that is supported at two points.It is subjected to a transverse load of F=50 daN.Calculate the deflection-denoted as A-of the beam under the action of the force F 0=10cm F=50 daN h=5mm 1) e=500 mm F=50 daN ep=2.5 mm 2) 瓶 ep ec=25 mm 安 2.We separate the beam of duralumin into two parts with equal thickness ep=2.5 mm,by imaginarily cutting the beam at its midplane.Each half is bonded to a parallel pipe made of polyurethane foam,making the skins of a sandwich beam having essentially the same mass as the initial beam (in neglecting the mass of the foam and the glue).The beam is resting on the same supports and is subjected to the same load F Calculate the deflection caused by F denoted by A'.Compare with the value of A found in Part 1.(Take the shear modulus of the foam to be:G=20 MPa.) Solution: 1.We will use the classical formula that gives the deflection at the center of the beam on two supports: F △= 48E1 with I= 12 2003 by CRC Press LLC18 APPLICATIONS 18.1 LEVEL 1 18.1.1 Simply Supported Sandwich Beam Problem Statement: 1. The following figure represents a beam made of duralumin that is supported at two points. It is subjected to a transverse load of F = 50 daN. Calculate the deflection—denoted as D—of the beam under the action of the force F. 2. We separate the beam of duralumin into two parts with equal thickness ep = 2.5 mm, by imaginarily cutting the beam at its midplane. Each half is bonded to a parallel pipe made of polyurethane foam, making the skins of a sandwich beam having essentially the same mass as the initial beam (in neglecting the mass of the foam and the glue). The beam is resting on the same supports and is subjected to the same load F. Calculate the deflection caused by F, denoted by D¢. Compare with the value of D found in Part 1. (Take the shear modulus of the foam to be: Gc = 20 MPa.) Solution: 1. We will use the classical formula that gives the deflection at the center of the beam on two supports: D F 48EI ----------- with I bh3 12 = = -------- TX846_Frame_C18a Page 343 Monday, November 18, 2002 12:40 PM © 2003 by CRC Press LLC