Development Of A Quick Approach For Engine Block High Cycle Durability Analysis

The present work deals with understanding the current process of estimating the fatigue safety factors for engine block. To capture the loading in cylinder block, real time rotating and reciprocating loads are applied at the initial firing angle and at every subsequent 5 or 10 degrees of crankshaft rotation. This could results in 144 or 72 analysis load steps to represent the complete cycle. This involves enormous computation time and adversely affects the design cycle time. This work involves the identification of the crank angles which contribute to maximum and minimum stresses that are acting during operation. Thereby reducing the number of analysis steps with a benefit of saving time and high performance computation and quicker design solution. A method is proposed to minimize the number of crank angles using Abaqus for estimating the engine block fatigue. Using the new approach reassessment was made on the fatigue calculation

Developments for the calculation of heavily loaded journal bearings

This thesis describes the development of an ElastoHydroDynamic (EHD) bearing calculation. The effect of body forces is shown to be important for highly loaded bearings in reciprocating internal combustion engines. Extension of the program to rotating machinery includes an examination of instability in the shaft bearings of a turbocharger. The development of a parameter to predict cavitation damage in a bearing is promising. Several calculation results using the program are shown. These are engine main bearing and connecting rod big-end bearings and full floating bearings for a turbocharger. The calculations on the big-end bearing if a racing engine show why the designers were having difficulty understanding the correct location for the oil feed hole position. Effects of elastic deformation, thermal deformation and manufacturing/assembly deformation all have a significant effect on the extent of the oil film. A novel calculation for a cavitation damage parameter is demonstrated successfully for a heavily loaded diesel engine bearing. The importance of body forces on the oil film due to high accelerations on certain bearings is shown to be theoretically important but not yet demonstrated. The program was written with the intention to be incorporated into the sponsoring company’s range of engine design software. A part of that development process included carrying out calculations to demonstrate to customers and present papers at conferences. The results of some of these calculations have been included in this thesis. Results of a study on the effect of crankshaft geometry on racing engine viscous friction losses were reported in a paper presented at the IDETC conference in Long Beach, 2005. This study used the first version of the software which only included Rigid Hydro Dynamics (RHD) at the time but was usable. Results of a study on stability of shaft motion in high speed turbocharger bearings were reported in a paper at the 8th International Turbocharger conference in London, 2006. At this time the program was still only capable of RHD calculations but could now solve for multiple oil films simultaneously and sweep through the speed range. The studies on the effects of body forces and the development of a cavitation parameter will be presented in papers in the near future

Prediction of 3D grinding temperature field based on meshless method considering infinite element

© 2018, Springer-Verlag London Ltd., part of Springer Nature. A three-dimensional numerical model to calculate the grinding temperature field distribution is presented. The finite block method, which is developed from meshless method, is used to deal with the stationary and the transient heat conduction problems in this paper. The influences of workpiece feed velocity, cooling coefficient, and the depth of cut on temperature distribution are considered. The model with temperature-dependent thermal conductivity and specific heat is presented. The Lagrange partial differential matrix from the heat transfer governing equation is obtained by using Lagrange series and mapping technique. The grinding wheel-workpiece contact area is assumed as a moving distributed square heat source. The Laplace transformation method and Durbin’s inverse technique are employed in the transient heat conduction analysis. The results of the developed model are compared with others’ finite element method solutions and analytical solutions where a good agreement is demonstrated. And the finite block method was proved a better convergence and accuracy than finite element method by comparing the ABAQUS results. In addition, the three-dimensional infinite element is introduced to perform the thermal analysis, and there is a great of advantages in the simulation of large boundary problems.The work was funded by China Scholarship Council, the Fundamental Research Funds for the Central Universities (N160306006), National Natural Science Foundation of China (51275084), and Science and technology project of Shenyang (18006001)

Numerical simulation of long and slender cylinders vibrating in axial flow applied to the Myrrha reactor

Flow induced vibrations are an important concern in the design of nuclear reactors. One of the possible designs of the 4th generation nuclear reactors is a lead-cooled fast reactor of which MYYRHA is a prototype. The combination of high liquid density, flow velocity, low pitch-to-diameter ratio and the absence of grid spacers makes this design prone to flow induced vibrations. Although most vibrations are induced by cross flow, axial flow around this slender structure could also induce vibrations. In order to gain insight in the possible vibrations (either induced by cross flow, axial flow or an external excitation) this study examines the change of eigenmodes and frequencies of a bare rod due to the lead-bismuth flow. To do so partitioned simulations of the fluid structure interaction are performed in which the structure is initially perturbed according to an in-air eigenmode

Strength analysis of small-dimension hub rubber torsional vibration damper

The article presents the dynamic strength analysis hub rubber torsional vibration damper. Numerical calculations were performed in the finite element method using commercial software Abaqus using explicit dynamic approach. Numerical simulations consisted of two calculation steps: the first was modeled pre-tension bolts at the second step hub was subjected to the action of a torsional vibration harmonics of predetermined amplitude and frequency coming from the shaft

Mechanical Responses of Engineering Materials and Lithium-Ion Batteries under Compression, Indentation and Rolling with Extensive Plastic Deformation.

Residual stresses due to indentation and rolling on a finite plate at very high loads were investigated by two-dimensional plane strain finite element analyses. The roller is modeled as rigid and elastic, and has frictionless contact with the elastic-plastic finite plate. The computational results indicate that the residual stresses after rolling are nearly the same for both roller models. For indentation and rolling with extensive plastic deformation, the computational results show that the contact pressure distributions are quite different and they are also significantly different from the elastic Hertzian pressure distribution. The computational results for the rolling case show a significantly higher longitudinal compressive residual stress and a lower out-of-plane compressive residual stress along the contact surface when compared to those for the single indentation case. Residual stress distributions in a rectangular bar due to rolling or burnishing with extensive plastic deformation are then investigated by three-dimensional finite element analyses. The computational results show that a higher rolling load does not necessarily always produce higher compressive residual stresses in the desired regions of the bar. The computational results are in agreement with the experimental results. Next, computational models are developed based on the Gurson's material model to account for the effect of porosity of the active materials on electrodes and separators for simulations of representative volume element (RVE) specimens of lithium-ion battery cells under constrained compression tests. The computational results show that the computational models can be used to understand and simulate the micro buckling of the component sheets, the macro buckling of the cell RVE specimens, and the formation of the kinks, shear bands and folds observed in experiments, and to simulate the load-displacement curves of the cell RVE specimens. Macro homogenized material models are adopted to model a small-scale lithium-ion battery module specimen under an in-plane constrained punch indentation test. The load-displacement responses of the computational results based on the hyperfoam and crushable foam material models compare well with the experimental results. The computational models for lithium-ion batteries developed in this research work can be used to design lithium-ion battery cells and modules in electric vehicles for crashworthiness.PHDMechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/98037/1/mdyusuf_1.pd

Simulation and experiment research of vibration characteristic on star compressor

Aiming at the vibration defects of star compressor, simulation and experiment are carried out to investigate the compressor. By drilling holes in the valve stem, the pressure changes of each cylinder are measured without damaging the cylinder block. The dynamic model of crank-connecting rod mechanism is established. After the measured cylinder pressure loaded on the dynamic model, the force acting on the main motion pair is obtained. The finite element model of the compressor is established for the first time, the force of the motion pair is loaded on the finite element model by MPC coupling method, and the vibration acceleration of the machine base is tested. The result shows that the main modal shapes between 50-150 Hz are body deformation, modal shapes between 150-200 Hz are base deformation, the simulation acceleration of the base is higher than that of the experiment, and the main working frequency and frequency doubling can correspond. The conclusions provide reference for vibration isolation design of star compressor

Study on Thermal Expansion of a V10 Engine Block Used in Shrink-Fit Assembling

The paper presents how a V10 engine block made of light alloys of aluminium is assembled with the cylinders casings made of grey cast iron alloys. The solution used in this case is shrink-fit technology. To obtain such an assembly it is required to study the phenomenon of thermal expansion of the bodies with complex geometries such as an engine block. The only viable solution to study the thermal phenomena for shrink-fit assembling is to use finite element methods for simulating. Five different cases are presented for the V10 engine block heating and for the optimal case, in which a clamping device is used for its positioning, the thermal expansions are determined. The final result is a mathematical relation which represents the dependences between the thermal expansions of the V10 engine block and temperatures

3D mechanical and thermal analysis of an Aluminium piston for a high-speed Diesel laboratory engine

A cast aluminium piston of a single cylinder Petter Diesel engine is modelled using the finite element method. The engine is intended to be supercharged, which will increase the thermal loading on the piston, and so the purpose of this work is to investigate the piston behaviour and strength when subjected to the current level of thermomechanical load. The dimensions of the piston and piston pin is measured, and the materials and boundary conditions are measured, calculated or assumed. Areas of particular interest were the combustion bowl rim and the piston pin boss. The latter was modelled using a contact interaction between the pin and boss, in order to accurately represent its behaviour. The final model is used to investigate the behaviour of the piston, locate the most critically stressed areas and the cyclical stress variations which may lead to fatigue. Local fatigue strength of the material is compared with local stress variations, and it is found that the piston is not exceeding its fatigue strength at any point and its expected lifetime should be quite high for the current loading of the engine.Et støpt aluminiumsstempel til en en-sylindret Petter Diesel motor er modellert ved bruk av elementmetoden. Det er planlagt at motoren skal superlades, noe som vil øke den termiske belastningen på stempelet. Formålet med dette arbeidet er å undersøke stempelets oppførsel og styrke under den nåværende termomekaniske belastningen. Dimensjonene på stempelet er målt, og materialer og grensebetingelser er målt, beregnet eller antatt. Spesielt interessante områder er kanten på forbrenningsskålen, og navet til krysspinnen. Sistenevnte ble modellert ved bruk at en kontakt-interaksjon mellom navet og krysspinnen, for å få en nøyaktig fremstilling av oppførselen til navet. Den endelige modellen er brukt for å undersøke oppførselen til stempelet, finne de mest utsatte områdene, og de sykliske stressendringene som kan føre til utmatting. Den lokale utmattingsfastheten til materialet er sammenlignet med de lokale stressendringene, og det er funnet ut at stempelet ikke overskrider utmattingsfastheten sin på noe punkt, noe som antyder en relativt høy levetid for stempelet under den nåværende belastningenMasteroppgåve i energiMAMN-ENERGENERGI399

Numerical analysis of the crankshaft of internal combustion engine

Koljenasto vratilo ili radilica je jedna od većih komponenata konstrukcije motora s unutrašnjim izgaranjem. Služi tome kako bi se linearan pomak klipa, kojeg guraju sile plinova nastale izgranjem goriva u cilindru, pretvorio u rotacijsko gibanje odnosno zakretni moment pogodan za pogon recimo automobila. Samo koljenasto vratilo veoma je složene geometrije i opterećenja. U ovom radu provedena je numerička analiza koljenastog vratila, kako bi dobili uvid u stanje naprezanja u ovom konstrukcijskom elementu i na temelju toga proveli analizu zamora. Prije same numeričke analize opisali smo koljenasto vratilo, probleme, način izrade, proveli analizu kinematike klipnog mehanizma te zatim i dinamike. Rezultati dobiveni analizom dinamike poslužili su nam kao ulazni podaci za numeričku analizu. Objašnjene su i verificirane metode i procedure primjenjene u numeričkoj analizi. Za potrebe numeričke analize korišteni su tetraedarski konačni elementi jer su se prilikom verifikacije i analize konvergencije pokazali prikladnima i jednostavnima za ovaj problem. Numerički proračun je proveden pomoću metode konačnih elemenata (MKE) u programskom paketu Abaqus. Numerički proračun također je proveden i u programskom paketu Solidworks s analogo postavljenim rubnim uvjetima i opterećenjem onome u Abaqus-u. Nakon toga pristupilo se analizi zamora u Solidwork-ovom modulu Fatigue analysis u kojem smo okvirno dobili vrijednosti životnog vijeka pojedinih dijelova koljenastog vratila kako bi u slučaju eksploatacije u realnom svijetu znali odrediti vremenske periode inspekcije koljenastog vratila.The crankshaft is one of the major components of the engine with internal combustion. Its purpose is to convert the linear displacement of the piston, which is pushed by the force of the gas generated by the ignition of fuel in the cylinder, into rotational motion or a torque suitable for the drive, for example the car drive. Crankshaft has very complex geometry, load and boundary conditions. Numerical analysis of the crankshaft was performed in order to gain insight into the stress state in this structural element and on that basis carried out the fatigue analysis. Prior to the numerical analysis we described the crankshaft, problems, way of producing, analysis of the kinematics of the piston mechanism and then the dynamics. The results obtained by analyzing the dynamics served us as input data for numerical analysis. The methods and procedures applied in the numerical analysis are explained and verified. For the purposes of numerical analysis, the tetrahedral finite elements were used because they proved to be appropriate and simple for this problem when verifying and analyzing convergence. Analysis was performed using the finite element method (FEM) in the Abaqus software. The numerical calculation was also carried out in the Solidworks software with an analogue set boundary conditions and load. After that, fatigue analysis in Solidwork's Fatigue Analysis module was obtained, in which we have roughly obtained lifetime values of individual crankshaft parts to determine crankshaft inspection time in case of real-world exploitation