CY2_t1。0 102。07 0。884 101。9 0。262 112。04 0。0485 94。51 1。098

CY1_t2。0 101。73 0。918 101。59 0。507 112。3 0。0474 50。36 1。104

CY2_t2。0 102。02 0。725 102。23 0。460 112。05 0。0707 50。5 1。101

Fig。 3。 Photograph of the test arrangement for 2 mm cylinder under axial compression, (a) initial set-up of specimen between instron platens, and (b) final set-up with the instron platen clamping the specimen to provide the required edge  supports。

Fig。 4。 Comparison of plot of experimental load against compression extension for cylinder with different radius-to-thickness ratios。

Table 4

Comparison  of  experimental  collapse  loads  with  theoretical  predictions    (Eavg

¼ average young's modulus, syp ¼ average upper yield stress)。

Fig。 5。 Plot of load against compression extension for cylinder CY1_t0。5。 Compar- ison of the experimental and numerical results。

After testing, cylinders were noticed to have an axisymmetric

  bulge through excessive plastic straining at the top ends, i。e。, at the

region where the load was applied。 This phenomenon can be at- tributed to the fact that both the localized stress and deformation at the region of load application is significant, and it tends to even out at a distance sufficiently removed from the region of load application。 However, post experimental visual observation re- vealed that there was ovalization at the top ends of the cylinder。 This is more pronounced for 2 mm cylinders and less pronounced as the thickness reduces。 The results of experimental collapse load

Table 5

Magnitude of experimental and numerical load with the corresponding compres- sion extension for cylinder CY1_t0。5。

ABAQUS Experiments

Load (kN) Compression extension Load (kN) Compression extension

(mm) (mm)

5 0。018 5 0。025

10 0。036 10 0。115

17。5 0。062 17。5 0。185

28。74 0。104 19 0。215

29。33 0。106 21 0。225

30。15