再论不均壁厚圆管的弹性失稳问题

STUDY SECOND TIME ON LOSS OF STABILITY OF THICK CIRCULAR PIPE OF NON-UNIFORM WALL THICKNESS

评述了在非均匀壁厚圆管的弹性失稳计算中应用“几何平均处理”方法及偏心水力活塞泵筒现场挤毁事例后，认为“几何平均处理”方法的有些做法需要给出证明，并用变截面压杆弹性失稳的临界压力计算说明该方法误差很大；偏心泵筒挤毁是在非弹性范围内发生的。还对原苏联学者耶内敏柯试验的技术背景，小挠度线弹性理论与非均匀壁厚薄壁圆管变形曲线的选择，以及影响近似解精度的几个因素进行了对比分析。最后指出，非均匀壁厚圆管的弹性失稳应在理论上进一步探索不同的近似解，同时也要积极筹备由于内外圆不同心引起的非均匀壁厚薄壁管的弹性失稳的试验工作。

Paying attention to the event of damage of the cylinder of eccentric hydraulic piston pump, the author gave a comment on application of geometric mean treatment method in calculation of elastic loss of stability of thick circular pipe of non-uniform wall thickness and demonstrated thrcugh the calculation of critical pressure of elastic loss of press bar with altered sections that the method results in a evident error and collapse of cylinder of eccentric pump takes place in the external elastic range. An analysis on technical background of the tests carried by Soviet scientist Yeneminko, theory of linear elasticity of minor bending deflection, choice of deformation curve of thin circular pipe with non-uniform wall thickness and a set of factors that affect accuracy of approximate solutions was described in the paper.The author pointed out that there is a necessity to search theoretically different approximate solutions of elastic loss of stability of circular pipe with non-uniform wall thickness and to carry tests upon elastic loss of stability of circular pipe of non - uniform wall thickness caused by eccentricity of external and internal circles.