Simulation Research on Pipeline-purposed Steel Bauschinger Effect under Different Loading Modes

The Bauschinger effect of the pipeline-purposed steel is simulated by the uniaxial tension-pressure test in two loading modes (i.e.,the pressure-tension mode and the tension-pressure mode).As a result it is identified that there exists obvious Bauschinger effect with the steel under the two loading modes,while the Bauschinger effect is greater in the pressure-tension mode.In different loading modes,the regularities of the influence by the initial strain on the final yield strength of pipeline steel are variable;and in the pressure-tension loading mode,the pipeline-purposed steel presents permanent softening characteristics,while in the tension-pressure loading mode,the said steel presents transient softening characteristics.