thick walled expansion joint spring rate
thick walled expansion joint spring rate
(OP)
dear All
have any body noticed that when "thickness of an expansion joint" exceeds that of the adjacent shell, the spring rate of expansion joint(calculated based on TEMA RCB.8) drops sudenly. while an increas in the spring rate is expected!!
example:
\
sheel thickness E.J. thickness Spring rate
20 mm 20 77108.547 Kgf/mm.
20 mm 21 48490.125 Kgf/mm.??
have any body noticed that when "thickness of an expansion joint" exceeds that of the adjacent shell, the spring rate of expansion joint(calculated based on TEMA RCB.8) drops sudenly. while an increas in the spring rate is expected!!
example:
\
sheel thickness E.J. thickness Spring rate
20 mm 20 77108.547 Kgf/mm.
20 mm 21 48490.125 Kgf/mm.??





RE: thick walled expansion joint spring rate
I ran several calculations on the PV Elite and I have had always an increase of the spring rate with the increase of the thickness of expansion joint wall, over the shell thickness. It would be interesting to share with us your explanation of the fenomena you noticed.
cheers,
gr2vessels
RE: thick walled expansion joint spring rate
RE: thick walled expansion joint spring rate
as far as I followed the procedure of TEMA 8th edition, in RCB-8.31 a discontinuity in parameters C6 and C7 was found ::!!!??
(it is shown in the attached file)
C6 and C7 are functions of C2 which is the ratio of shell thickness to expansion joint thickness. probably this sudden jump in the value of C6 and C7 (which ocures at C2=1) will result in a decreas of spring rate when the thickness of expansion joint exceeds that of the shell!!
I do not know if this discontinuity was delibrately and has a mechanical justification or it is a mistake?
Any help is appreciated!!