The Research On Fretting Fatigue Of Diesel Cylinder Block

The diesel cylinder block is constitute the skeleton of engine，and is the installfoundation of each institution and each system。The engine parts and accessories installedinside or outside，it should bear all kinds of loading，such as low frequency load、highfrequency load、direct or indirect load、low-rising or high amplitude vibration，sometimes，the contact parts would bear some cyclic load，so that，the surface between two parts wouldhave some smaller sliding. Therefore the diesel cylinder block must have enough strength andstiffness. Even if we have meet the design requirements in the design process, the dieselcylinder block is still possible failure during the working process, by investigating its reasons,most of the reason is caused by fretting fatigue of diesel cylinder block. Nowadays，thefretting fatigue has become one of the main failure what lead the diesel cylinder block out ofwork. This paper regard the fretting fatigue of the diesel cylinder block-the main bearingcover contact surface as the research object, through the analysis of combination model andits simulation finite element, combined with the critical surface fatigue parameters, predictionthe location of fretting fatigue fissure.In this paper, through research the research achievement of fretting fatigue andclassification the seriousness of fretting fatigue damage failure and fretting fatigue damagemechanism in detailed summary. regard the fretting fatigue of the diesel cylinder block-themain bearing cover contact surface as the research object, and the fretting fatigue relatedtheory with the finite element analysis method as the study foundation, has carried on thediesel cylinder block-the main bearing cover and its simulation’s stress and strain analysis inthe condition of zero (pre-tightening condition) and circulation condition (outbreak condition),and combined with critical surface fretting fatigue parameters, predict the location of frettingfatigue fissure. Finally, we have checked the two fretting fatigue fissure location which take place on the diesel cylinder block-the main bearing cover and its simulation.Comparing the latest contact model, according to the diesel cylinder block-the mainbearing cover aspects of the contact type, we have selected the square foot bridge-aidedanalysis specimen model, and then in accordance with the diesel cylinder block-the mainbearing cover contact characteristics to set the simulation’s geometry size. Depending on thetype of test to select the Changchun Haoyuan machine company’s product-HYS-100typemicrocomputer control of electro-hydraulic servo fretting fatigue testing machine.Using three-dimensional modeling software Pro/e, respectively to set up the entitymodeling of the diesel cylinder block-the main bearing cover and its simulation, and using thefinite element software ANSA to discrete the model, and the finite element analysis softwareis used to set the boundary conditions of the model, to obtain the stress and strain data. While,we may get the stress nephogram and deformation nephogram when the models in thecondition of zero (pre-tightening condition) and circulation condition (outbreak condition),using the critical fatigue parameters SWT and FS parameters to predict the location of frettingfatigue fissure most likely initiation point on the diesel cylinder block-the main bearing covercontact surface.By checking the two most likely initiation points of two models, to determine thesimulator is proper and its size is suit for the back of test.