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Angle of rotation of the bi-directional FG micro-tube when (a) llo = lli = 0, (b) llo/lli = 0.2, (c) llo/lli = 1.0, and (d) llo/lli = 2.0.

Angle of rotation of the bi-directional FG micro-tube when (a) llo = lli = 0, (b) llo/lli = 0.2, (c) llo/lli = 1.0, and (d) llo/lli = 2.0.

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This study aims to characterize the twisting behavior of bi-directional functionally graded (FG) micro-tubes under torsional loads within the modified couple stress theory framework. The two material properties involved in the torsional static model of FG small-scale tubes, i.e., shear modulus and material length scale parameter, are assumed to pos...

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