Chapter 5 Internal Loads

Question 1

purpose of structure analysis

Answer 1

determining the internal loads (stresses and strains of all components)

Question 2

result of finite element method

Answer 2

system stiffness matrix x deformation vector = system load vector

Question 3

simplified stick model is …

Answer 3

… statically determined

Question 4

local (cross-section) coordinate system

Answer 4

perpendicular to the section of interest

Question 5

cross-sectional centres

Answer 5

1. centre of gravity
2. elastic centre of bending
3. elastic centre of shear / torsion / twist (shear centre)

Question 6

centre of gravity

Answer 6

centre of the gravitational and inerta forces of the cross-section

density-weighted sum of all position vectors of the cross-section

Question 7

elastic centre of bending

Answer 7

y-axis is the neutral fibre for bending around y and z-axis is the neutral centre for bending around z

elastic modulus weighted sum of all position vectors of the cross-section

in a homogenous material elastic centre of bending and centre of gravity are identical

Question 8

shear centre

Answer 8

point where the resultant of shear stresses passes through

point in the cross section through which shear loads produce no twisting

Question 9

quarter chord point

Answer 9

point where aerodynamic loads are applied

there is pitching moment