CAJ | 학술논문

热棘轮失效是薄壁圆筒的主要失效模式之一，现有ASME锅炉及压力容器规范和EN13445等设计标准主要考虑环向应力，而未考虑轴向应力条件，使得设计结果可能偏于不安全。针对循环热-机械双轴载荷下薄壁圆筒热棘轮设计理论的不足，采用非循环分析方法系统研究双轴应力状态下薄壁圆筒热棘轮极限的解析解，重点考虑轴向压缩应力对循环温度梯度和稳定内压组合载荷下薄壁圆筒热棘轮极限的影响，并提出相应的设计方法，并采用有限元法对理论结果进行验证。结果表明，循环热-机械载荷下轴向压缩应力会显著降低薄壁圆筒的热棘轮极限，且理论解与有限元分析结果吻合良好，这说明此方法可用于循环热-机械双轴载荷及类似工况下薄壁圆筒的热棘轮设计限，具有良好的工程价值。
열극륜실효시박벽원통적주요실효모식지일，현유ASME과로급압력용기규범화EN13445등설계표준주요고필배향응력，이미고필축향응력조건，사득설계결과가능편우불안전。침대순배열-궤계쌍축재하하박벽원통열극륜설계이론적불족，채용비순배분석방법계통연구쌍축응력상태하박벽원통열극륜겁한적해석해，중점고필축향압축응력대순배온도제도화은정내압조합재하하박벽원통열극륜겁한적영향，병제출상응적설계방법，병채용유한원법대이론결과진행험증。결과표명，순배열-궤계재하하축향압축응력회현저강저박벽원통적열극륜겁한，차이론해여유한원분석결과문합량호，저설명차방법가용우순배열-궤계쌍축재하급유사공황하박벽원통적열극륜설계한，구유량호적공정개치。
Thermal ratchet is the typical failure mode for thin-walled cylinder. Only the hoop stress is used for ratchet limit design in the ASME boiler and pressure vessel code as well as EN 13445 design standards, while the axial stress is not considered. Hence, the design results may be unsafe under this case. In view of the shortage of ratchet limit design theory for thin-walled cylinder under cyclic biaxial thermo-mechanical loadings, the ratchet limit analytical solution of thin-walled cylinders subjected to biaxial thermo-mechanical loads has been derived according to the non-cyclic method. The effect of axial compressive stress on the thermal ratchet limit of thin-walled cylinder under cyclic temperature gradient and constant internal pressure is stressed, and the corresponding design method is proposed. The closed-form solutions are validated by simplified finite element method. Results revealed that the axial compressive stress significantly decreases the ratchet limit of thin-walled cylinders under biaxial loadings. Moreover, the proposed analytical solutions are in well agreement with those finite element method(FEM) results. This shows that the proposed design method has good engineering significance for evaluating the ratchet limit of thin-walled cylinders under cyclic biaxial thermo-mechanical loadings.