可压缩理想塑性体中逐步扩展裂纹顶端的弹塑性场
ELASTIC-PLASTIC FIELDS NEAR CRACK TIP GROWINGSTEP-BY-STEP IN A COMPRESSIBLE-PERFECTLYPLASTIC SOLID
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摘要: 本文利用理想塑性固体平面应变问题的基本方程,分析了可压缩理想塑性体中逐步扩展裂纹顶端的弹塑性场,得到了关于应力的渐近场,分析了弹性卸载区的演变过程和修正的中心扇形区的发展过程,预示了出现二次塑性区的可能性,弹性可压缩性的影响明显表现在经典的中心扇形区必需加以修正,垂直于板面方向的应力偏量不再为零,而且随着新裂纹面的形成,裂纹前方的均匀应力场和紧连着的修正的中心扇形区的应力偏量将发生变化,这种变化是由于垂直于板面方向的应力偏量发生变化造成的。Abstract: The elastic-plastic fields near the crack tip growing step-by-step in a compressf-ble-perfectly plastic solid are analysed based on the fundamental equations for plane strain pro-blem of perfectly plastic solid, and the asymptotic solutions for stress field near the crack tip are obtained. The solutions show both the evolution process of elastic unloading domain and predict the possibility of the secondary plastic domain. The classical central fan domain must be rec-tified and the stress deviatoric stress n...