Presence Of Axial Force Research Articles

Creep of Pipes Under Axial Force and Twisting Moment

The load-deformational behavior of twisting of pipes in the presence of axial force is examined. Based on the small deformation theory, charts and curves, which relate the twisting moment, axial force, and twist rate per unit length, are presented for the design of pipes with creep. The accuracy of the results are demonstrated by comparing the maximum stress and twist rate due to pure tension of fairly heavy pipes, with that of more exact thick-walled cylinder solutions.

Stirrup Effectiveness in Reinforced Concrete Beams with Axial Force

A study of the effectiveness of web reinforcement in reinforced concrete beams subject to axial forces is reported, involving the testing of 60 simply supported reinforced concrete T-beams and eight restrained reinforced concrete T-beams. The primary variables were axial force, the amount of web reinforcement, the concrete strength, and the shear span to depth ratio. Secondary variables were the web reinforcement yield point and the amount of flexural reinforcement. Measurements were made of applied loads, deflections, web reinforcement strain, and diagonal tension crack width. The effectiveness of the web reinforcement was found to be unaffected by the presence of axial forces. The design procedures for beams with web reinforcement contained in the ACI Building Code, ACI 318-63, were found to be conservative. Relationships are proposed which more closely reflect the variation of ultimate shear strength with variation of relevant parameters.

Limit analysis of arches

In the limit analysis of frames it is usually assumed that the limiting bending moment of a cross section is not significantly reduced by the presence of axial forces. In the limit analysis of flat arches this assumption is not permissible as a rule. In the present paper the basic concepts of limit analysis are extended to members in which axial forces as well as bending moments must be taken into account. Methods of determining the critical load intensity of arches are developed and illustrated by numerical examples.