Abstract : in order to bring the material function into play the ramp load method demands the flange rigidification with great range and deep layer 文摘:坡道载荷设计法要求半轴法兰圆角大直径范围和杆部深层硬化，以充分发挥材料的潜力，实现强度与塑性的合理配合。
2.
Experimental and calculated results showed that creep proceeded in two phases and andrade theory could simulate appropriately the creep constitutive relations of pmma in single dimension . furthermore , the accumulation theory in low stress and the strain - rigidification theory in the first phase of creep could also describe approximately the constitutive relations of pmma 实验与计算结果表明，蠕变明显地分为两阶段， andrade理论能很好地模拟pmma材料在恒定应力作用下的一维蠕变型本构关系；陈化理论在低应力水平下及应变硬化理论在蠕变第一阶段也可近似地描述pmma的本构关系。
3.
Basing on experiments , the creep constitutive relations of pmma were researched . creep experiments of single dimension were done on three specimens with no defects under constant stress and the andrade theory , the accumulation theory , the strain - rigidification theory , the norton theory were applied to fit the experimental data 做了三组恒定应力条件下的无缺陷pmma试件的蠕变实验，分别用andrade理论、陈化理论、应变硬化理论及恒速理论对实验数据进行了拟合。
