Buckling of Thin-Walled Circular Cylinders Under Axial Compression and Internal Pressure

Abstract

Theoretical studies show that the effect of internal pressure on the buckling of thin-walled circular cylinders under axial compression depends on the dimensionless parameter p = (p/E) (R/t) 2 where p is the internal pressure, E the modulus of elasticity, R the cylinder radius, and t the wall thickness of the cylinder. The theoretical treatment of Lo indicates that the critical buckling stress should increase with increasing values of p up to a value of p t3 0.169, after which the buckling stress remains constant at a value equal to that given by the small deflection theory. Since previous experimental data were limited to values of p less than 0.10, additional experimental data were obtained up to p & 2.0 to check the theoretical values. The present tests show that Lo's theory, with certain significant modifications in interpretation, is in fair agreement with the experimental results. A proposed design method is presented which, it is believed, will give conservative values for the buckling stress of such cylinders.A series of photographs showing the variation of the buckling pattern with the internal pressure is one of the most interesting features revealed by the present series of experiments. SYMBOLS E K L P V PB P -1 cr R t O'er O'er *cr0 Ad-cr = = = = = = = = = = = = =Young's modulus, psi another conventional symbol for a cr length of cylinder, in. internal pressure, psi nondimensional internal pressure = (p/E)(R/t) pressure in loading bellows, psi total compressive load at buckling, lbs. radius of cylinder, in. cylinder wall thickness, in. critical compressive stress at buckling, psi nondimensional buckling stress = (o-cr /E)(R/t) KQ -value of d-cr at zero internal pressure O'er O'er

A novel energy pile: The thermo-syphon helical pile

“…This deformation may lead to sudden collapse of the pipe if it fails to sustain the deformation. According to Lo et al [80], Fung and Sechler [81] and Paquette and Kyriakides [82], low internal pressures will help the pipe wall to maintain an upright position. However, when the internal pressure exceeds a certain limit, it facilitates the propagation of wrinkles and causes bifurcation failure.…”

“…However, when the internal pressure exceeds a certain limit, it facilitates the propagation of wrinkles and causes bifurcation failure. Lo et al [80] and Fung and Sechler [81] used the following equation to define a dimensionless limit of bifurcation, p p :…”

“…where p is internal pressure, E is modulus of elasticity, R is radius, and t is the thickness of the pipe wall. Fung and Sechler [81] suggested that the dimensionless limit of bifurcation p p should be limited to 0.2 to minimize the likelihood of bifurcation under the applied internal pressure and axial compression.…”

Divergent effect of electric fields on the mechanical property of water-filled carbon nanotubes with an application as a nanoscale trigger

“…The axial pressure provides an additional axial support to the CNT end, which would enhance the mechanical property of CNTs. As for the circumferential pressure, the elastic modulus measured by compressive loading would be slightly reduced due to the Poisson's ratio, whereas the critical buckling stress would be increased according to the classical stability theory about the shell under the combined axial compression and internal pressure (the increment up to about 50% with the nondimensional internal pressure) [48][49][50]. For the water-filled CNTs, during the compression process, the axial pressure gradually increases and plays a dominant role in resisting the axial compression, which induces an increase in the elastic modulus.…”