Twisting moment

If a torsional couple or twist moment Mz were applied to the two spheres in contact, the contact surface would undergo a rigid rotation relative to distant points in each body if there were no-slip motion at the interface. In this case, the tangential displacements could be expressed by... 

It can be seen that the boundary value of Eq. (2.120) matches that given by Eq. (2.112). The twisting moment is given by... 

Figure 2.14. Twist angle and tangential traction by torsion (from Lubkin, 1951) (a) Twist moment Mz versus total twist angle fi (b) Typical distribution of tangential traction.

T absolute temperature (twisting moment) period kinetic energy. 

When reinforcement is required for elliptical or obround openings and the long dimension exceeds twice the short dimension, the reinforcement across the short dimension shall be increased to guard against excessive distortion due to twisting moment [1, Section UG-36(a) (1)]. 

With most typical sandwich constructions, the faces provide primary stififhess under in-plane shear stress resultants (Nxy), direct stress resultants (N, Ny), and bending stress resultants (Mx, My) (Figure 7.48). Also as important, the adhesive and the core provide primary stiffness under normal direct stress resultants ( z), and transverse shear stress resultants (Q, Qy). Resistance to twisting moments (T, TyJ that is important in certain plate configurations, is improved by the faces. Capacity of faces is designed not to be limited by either material strength or resistance to local buckling. 

Figure 8.27 Fibrous glass-reinforced plastic thin-wall cylinder (a) internal pressure alone and (b) internal pressure plus twisting moment...

P(3) An eccentrically loaded connection is a connection where the line of action of the applied load does not pass through the centroid of the fastener group. The connection is subjected to a twisting moment in addition to a concentric force. Bracket-type connections, web splices in beams, and standard beam connections are common examples of eccentrically loaded connections (see Figure 5.10). 

The differential equations for the force and moment resultants, in terms of stress and strain, are then solved to obtain the maximum bending moments, twisting moments and deflections. 

Stripping torque n. (1) Of a self-tapping screw, the twisting moment in Nm required to strip the threads formed by the screw in a softer material. (2) Of a molded-in insert, the torque required to break the mechanical bond between the plastic and the insert s knurled surface. 

Shear on weld due to twisting moment in horizontal direction, fth, and vertical direction, ftv... 

Wang, T. T., Zupko, H. M., Wyndon, L. A. and Matsuoka, S., Dimensional and volumetric changes in cylindrical rods of polymers subjected to a twist moment. Polymer, 1982, 23, 1407-1409. 

T. T. Wang, H. M. Zupko, L. A. Wyndon, and S. Matsuoka, Dimensional and Volumetric Changes in Cylindrical Rods of Polymers Subjected to a Twist Moment Polymer 23, 1407-1409 (1982). 

Figure 6-48. A fiberglass-reinforced plastic thin-walled cylinder with internal pressure plus twisting moment.

Resistance to twisting moments (T TyJ, which is important in certain plate configurations, is improved by the faces. Capacity of faces is designed not to be limited by either material strength or resistance to local buckling. 

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