Handbook Plastic Pipe Ringstiffness 5
Determination of the deformation of the segment
The segment is deformed to an extent as it would be during a deformation of the whole pipe of 3%. The deformation of the segment is calculated according to the following equation:
YRS = YS X α79O = 0.03 X di x 0.29
YRS = deformation of pipe segment (mm), which corresponds to a pipe-deformation of 3%
YS = the vertical deformation of the pipe (mm), which corresponds to a pipe-deformation of 3%
α79 = conversation factor for deformation of 79o segment = 0.296 (devired analytically)
Calculating the ring stiffness
The ring stiffness S of each test body can be calculated with the formula
S = (0.0186+0.025xYs/di)xF79α/(LxYs)
F79a = test force when deformation of pipe segment YRS is achieved (kN)
Ys = vertical deformation of the pipe (m)
di = inner diameter of pipe segment (m)
L = length of pipe segment (m)