Scholarlink

<p>To address cracking issues in compacted graphite cast iron (CGI) exhaust pipes under pollution control and thermal efficiency requirements, temperature, stress, and strain were analyzed using a 3D thermal-mechanical model. The stress concentration phenomenon in the exhaust pipe was improved using a structure-material coupling optimization method. The optimization scheme for Nb-alloyed CGI was evaluated. The results showed stress concentration at the transition angles of each branch pipe and the reinforcing ribs. Structural optimization was achieved by increasing the radius of the rounded corners and removing the reinforcing ribs, reducing peak stress by 26.2 % and 5.63 %, respectively. Material evaluation indicated that thermal expansion coefficient and wall thickness are the primary factors affecting fatigue life. By combining the comprehensive weights of the entropy method and the analytic hierarchy process (AHP), CGI containing 0.05–0.07 wt% Nb was identified as the optimal material for enhancing fatigue life.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Enhancing the fatigue life of low-niobium compacted graphite cast iron exhaust pipes using multi-physical field coupled analysis and optimal design

  • 期刊论文

  • 发表日期：

    2026年1月9日

查看全文
  • Yongchuan Lin,
  • Lusheng Liu,
  • Yudong Zhang,
  • Debin Lai

摘要

To address cracking issues in compacted graphite cast iron (CGI) exhaust pipes under pollution control and thermal efficiency requirements, temperature, stress, and strain were analyzed using a 3D thermal-mechanical model. The stress concentration phenomenon in the exhaust pipe was improved using a structure-material coupling optimization method. The optimization scheme for Nb-alloyed CGI was evaluated. The results showed stress concentration at the transition angles of each branch pipe and the reinforcing ribs. Structural optimization was achieved by increasing the radius of the rounded corners and removing the reinforcing ribs, reducing peak stress by 26.2 % and 5.63 %, respectively. Material evaluation indicated that thermal expansion coefficient and wall thickness are the primary factors affecting fatigue life. By combining the comprehensive weights of the entropy method and the analytic hierarchy process (AHP), CGI containing 0.05–0.07 wt% Nb was identified as the optimal material for enhancing fatigue life.