Analysis of fatigue crack growth in cylinder head bolts of gasoline engine based on experimental data
Autor: | Karim Aliakbari, Tohid Akbarpour Mamaghani |
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Rok vydání: | 2020 |
Předmět: |
0209 industrial biotechnology
Materials science business.industry Mechanical Engineering Applied Mathematics Ratchet General Engineering Aerospace Engineering 02 engineering and technology Structural engineering Thread (computing) Paris' law Industrial and Manufacturing Engineering Finite element method 020901 industrial engineering & automation Cylinder head Automotive Engineering Cylinder block business Stress intensity factor Petrol engine |
Zdroj: | Journal of the Brazilian Society of Mechanical Sciences and Engineering. 42 |
ISSN: | 1806-3691 1678-5878 |
Popis: | Engines cylinder head bolts failure from the thread location in cylinder block causes the problems during repairing time. Exact prediction of fatigue crack growth in bolts by experimental analysis and finite element method modeling can affect the Maintenance Planning and Scheduling Implementation. In this study, the fatigue analysis of cylinder head bolts of a four-cylinder gasoline engine imposed by premature failure is investigated. The bolts suffer a mechanical seizure on the threads about 2 × 108 cycles in service. For such aim, standard specimens are cut off from the bolts and examined to evaluate the mechanical properties and material chemical composition. Optical microscopes and scanning electron microscopy are employed to consider the microstructures, defects, fracture surface and failure cause. The morphology of the fracture surface shows the fatigue crack growth marks, including the beachmarks, the ratchet marks and the river cracks. The finite element analysis model is presented applying the elastic–plastic finite element analysis for the bolts under variable combustion pressure. The stress history is then used to calculate stress intensity factors and fatigue life of bolts. Numerical results show that crack existence to depth of 0.35 mm is the source of failure of premature fracture. |
Databáze: | OpenAIRE |
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