低合金钢管道环焊缝接头焊接应力应变规律研究-材料加工工程专业论文.docxVIP

万方数据 万方数据 Abstract Pipes structures are widely used in the vital departments of national economy, such as chemical and oil industries. The residual stress and strain produced during the welding process will affect the service life of components. So, carrying out the study on the law of welding stress and strain in circumferential joint, discuss the effect of material properties, pre-deformation, prestress, heat treatment, etc. and compare the results under different models can provide theoretical basis to control, adjust and reduce the welding residual stress and strain, which are of important academic value and practical significance. This paper is based on the thermal-elastic-plastic theory and the platform of ANSYS finite element software. Plate element model, shell element model and three-dimensional model element model of welding temperature field and stress-strain field in circumferential joint of Low Alloy Steel Pipes are founded and influence law of various parameters on the welding stress and strain is discussed. The residual stresses of circumferential joint are measured using the blind hole method, which are compared and verified with values of the finite element method. The paper covers the following aspects concerning the main work and research in the project. A two dimensional plate element axisymmetric model of welding temperature field and stress-strain field in circumferential joint is founded III and the distribution of temperature field and stress-strain field during the welding process are obtained. Parameters such as the mesh density, weld model, heat source model are optimized and the influential trend of thermal conductivity, specific heat, thermal expansion coefficient to the welding strain are obtained in this paper. A shell element model of welding temperature field and stress-strain field is founded, whose welding residual stress and strain distribution are obtained. The distribution of axial stress is related to the additional bending str