在航空发动机叶片设计过程中,需要进行叶片罩量优化来减小多种载荷引起的弯曲应力,改善其应力状况。为了提高叶片罩量优化设计效率,根据Kri gi ng近似模型和试验采样技术,提出了1种叶片罩量优化设计方法。利用序列采样方法逐步改善近似...在航空发动机叶片设计过程中,需要进行叶片罩量优化来减小多种载荷引起的弯曲应力,改善其应力状况。为了提高叶片罩量优化设计效率,根据Kri gi ng近似模型和试验采样技术,提出了1种叶片罩量优化设计方法。利用序列采样方法逐步改善近似模型预测精度,然后在近似模型上进行全局寻优。结果表明:该方法简单易用,通过构造近似模型代替真实的物理模型,降低了计算成本,提高了优化效率。优化后的叶片最大等效应力减小了12.43%,有效地减小叶片的峰值应力。展开更多
The hydro-hammer sampler is a new type of sampler compared with traditional ones. An important part of this new offshore sampler is that the structure of the core cutter has a significant effect on penetration and cor...The hydro-hammer sampler is a new type of sampler compared with traditional ones. An important part of this new offshore sampler is that the structure of the core cutter has a significant effect on penetration and core recovery. In our experiments, a commercial finite element code with a capability of simulating large-strain frictional contact between two or more solid bodies is used to simulate the core cutter-soil interaction. The effects of the cutting edge shape, the diameter and the edge angle on penetration are analyzed by non-liner transient dynamic analysis using a finite element method （FEM）. Simulation results show that the cutter shape clearly has an effect on the penetration and core recovery. In addition, the penetration of the sampler increases with an increase in the inside diameter of the cutter, but decreases with an increase in the cutting angle. Based on these analyses, an optimum structure of the core cutter is designed and tested in the north margin of the Dalian gulf. Experiment results show that the penetration rate is about 16.5 m/h in silty clay and 15.4 m/h in cohesive clay, while the recovery is 68% and 83.3% resoectively.展开更多
文摘在航空发动机叶片设计过程中,需要进行叶片罩量优化来减小多种载荷引起的弯曲应力,改善其应力状况。为了提高叶片罩量优化设计效率,根据Kri gi ng近似模型和试验采样技术,提出了1种叶片罩量优化设计方法。利用序列采样方法逐步改善近似模型预测精度,然后在近似模型上进行全局寻优。结果表明:该方法简单易用,通过构造近似模型代替真实的物理模型,降低了计算成本,提高了优化效率。优化后的叶片最大等效应力减小了12.43%,有效地减小叶片的峰值应力。
基金Project 20002070005126 supported by the China Geological Survey
文摘The hydro-hammer sampler is a new type of sampler compared with traditional ones. An important part of this new offshore sampler is that the structure of the core cutter has a significant effect on penetration and core recovery. In our experiments, a commercial finite element code with a capability of simulating large-strain frictional contact between two or more solid bodies is used to simulate the core cutter-soil interaction. The effects of the cutting edge shape, the diameter and the edge angle on penetration are analyzed by non-liner transient dynamic analysis using a finite element method （FEM）. Simulation results show that the cutter shape clearly has an effect on the penetration and core recovery. In addition, the penetration of the sampler increases with an increase in the inside diameter of the cutter, but decreases with an increase in the cutting angle. Based on these analyses, an optimum structure of the core cutter is designed and tested in the north margin of the Dalian gulf. Experiment results show that the penetration rate is about 16.5 m/h in silty clay and 15.4 m/h in cohesive clay, while the recovery is 68% and 83.3% resoectively.
