Page 606 - Aircraft Stuctures for Engineering Student

Index 587

principal curvatures 127 Sandwich panels 230,23 1
principal moments 127 Secant modulus 173
pure bending 122-5 Second moments of area of inclined and
secant modulus 173 curved thin sections 288,289
strain energy in bending and twisting 142, Semi-inverse method for elasticity problems
143 41,43-8
subjected to a distributed transverse load Semi-monocoque structures 223
129-37 Shear centre 295,298-300, 304-7, 392
synclastic surface 125 Shear lag, see Structural constraint
tangent modulus 173 Shear lines 57
total potential energy 147 Shear of closed section beams 300-7
Poisson's ratio 25 alternative method for the calculation of
limiting value 26 shear flow distribution 340, 341
Polar second moment of area of a thin- shear centre 304-7
walled column 184 shear flow distribution 300-2
Potential energy 70, 71, 73-6, 144-9, 165-9 twist and warping 303,304
Prandtl stress function, see Torsion of solid Shear of fuselages, see Stress analysis of
sections aircraft components
Principal axes of a beam section 81 Shear of open section beams 295-300
Principal planes 11 alternative method for the calculation of
Principal strains 23 shear flow distribution 340, 341
Principal stresses 11, 12 shear centre 298-300
Principle of stationary value of total shear flow distribution 295-8
complementary energy 76, 77 Shear of wings, see Stress analysis of aircraft
application to deflection problems 77-85 components
application to statically indeterminate Shear stress distribution at a built-in end of
systems 85-100 a closed section beam 445-8
Principle of stationary value of total Slenderness ratio of a column, see Columns
potential energy 73-6, 142-9 Southwell plot
Principle of superposition 103 columns 162
Principle of virtual work 71-3 plates 174
virtual displacements 7 1, 72 Stability of beams under transverse and
virtual forces 72, 73 axial loads 162-5
Principles of stressed skin construction Stainless steel, see Materials of aircraft
21 1-32 construction
Statically determinate systems 24
Rayleigh, Lord 103, 565 Statically indeterminate systems 24, 85-100
Rayleigh-Ritz method Stiffened panels 175-80
bending of a beam 75 failure stress 177-80
buckling of columns 168 instability 175-7
oscillation of beams 565-8 Strain 16-32
thin plates 142-9 definition 17
Reciprocal theorem 68 experimental measurement 28-32
Reduced elastic modulus of a column 159 longitudinal or direct strain 16- 18
maximum shear strain 23
Safe life structures, see Fatigue Mohr's circle 23, 28
St. Venant, B. de plane strain 20, 37, 38
principle 42 principal strains 23
semi-inverse method 41, 43-8 shear strain 16, 18, 19
warping function, see Torsion of solid strain gauge rosette 29
sections strains on inclined planes 21, 22