Multiaxial Fatigue Life Analysis Of Additive Manufacturing Titanium Alloys Based On Abaqus And Fe-Safe

Additive manufacturing,as a revolutionary advanced manufacturing technology,is being rapidly introduced into biomedical research,aircraft and aerospace industry and other important fields,and has become a research focus in the field of processing.In the process of additive manufacturing,due to the difficulty of process control and complex influencing factors,it is inevitable to form internal defects such as pores,powder unfused zone and high residual stress.In addition,the additive manufacturing component is often subjected to the cyclic action of multi-axis load when it is in service.At present,the research on fatigue performance of additive manufacturing component under multi-axis load is scarce.Therefore,it is of great practical significance to study the prediction of multiaxial fatigue life of additive manufacturing materials.In this paper,the additive Ti6Al4 V alloy material is selected and the fatigue life prediction platform based on Abaqus and Fe-safe is used to predict the multi-axial fatigue life of the material.The specific research content is as follows:(1)The multi-axis fatigue life prediction criteria are summarized,and the principles of several multi-axis fatigue life prediction models and the prediction methods of multi-axis fatigue life of notched parts are introduced in detail.(2)The multi-axis fatigue prediction method based on Abaqus and Fe-safe platforms was introduced and compared with the experimental results.After the feasibility of the method was confirmed,the fatigue life of the Ti6Al4 V alloy chipped parts under multi-axis proportional loading and non-proportional loading was predicted.The results show that the fatigue life of the model under non-proportional loading is much higher than that under proportional loading under the same stress state.(3)The life prediction of several fatigue life models was evaluated and it was found that the fatigue life prediction model based on von-Mises equivalent stress was the most accurate for low cycle fatigue,but the overall prediction result of high cycle fatigue was larger than that of the Smith-Waston-Topper(SWT)model.The overall prediction result of the Morrow-Brown-Miller model is small,which is the least accurate.Using relatively accurate fatigue life models in different working conditions,it is found that with the increase of phase difference,the multi-axial fatigue life of the model is increasing,and the increasing speed is faster and faster.The multiaxial fatigue life also increases significantly with the increase of stress ratio.Orthogonal test was designed to analyze the effect of surface integrity on multiaxial fatigue life of additive Ti6Al4 V titanium alloy.Both range and variance analysis show the degree of influence of various factors: residual stress,notch size,surface roughness.It provides a way to optimize the manufacturing process and posttreatment process of additive Ti6Al4 V titanium alloy and improve the fatigue life of components efficiently.