Marine crankshaft forgings are the key components in the ship power system, and their fatigue life and reliability are of great significance to the safety and economic benefits of the ship. This paper discusses the fatigue life and reliability evaluation of Marine crankshaft forgings.
Fatigue life refers to the service life of crankshaft forgings under the action of alternating loads. Marine crankshaft forgings will be subjected to periodic alternating loads during operation, such as engine torque, speed, etc. This alternating load will lead to fatigue cracks in crankshaft forgings and reduce their fatigue life.
In order to evaluate the fatigue life of crankshaft forgings, the following methods can be used:
Stress-life curve method: Obtain the life data of crankshaft forgings under different stresses through experiments, draw the stress-life curve, so as to determine its fatigue limit and fatigue life.
Fatigue crack growth rate method: The crack growth rate data of crankshaft forgings under different stresses are obtained through experiments, and the relationship between crack growth rate and stress is established to predict the fatigue life.
Reliability evaluation refers to the evaluation of the failure probability of crankshaft forgings under specific conditions. Marine crankshaft forgings will be affected by many factors during operation, such as temperature, humidity, vibration, etc., these factors may lead to the failure of crankshaft forgings.
In order to assess the reliability of crankshaft forgings, the following methods can be used:
Probability method: The failure data of crankshaft forgings are obtained by experiment, and the failure probability and reliability index are calculated by probability method.
Failure Mode and Impact Analysis (FMEA) : The failure mode of crankshaft forgings is analyzed to determine its potential failure mode and impact, so as to assess its reliability.
Reliability test: By simulating the actual operating conditions of the crankshaft forging reliability test, obtain its failure data under specific conditions, so as to evaluate its reliability.
The fatigue life and reliability evaluation of Marine crankshaft forgings is an important link to ensure the safety of ship operation. By evaluating the fatigue life of crankshaft forgings, the service life of crankshaft forgings under alternating load can be known. By evaluating the reliability of crankshaft forgings, the failure probability of crankshaft forgings under certain conditions can be known. These evaluation results can provide important reference for ship design, manufacture and use to ensure the safety and economic operation of ships. At the same time, with the continuous progress and development of science and technology, new evaluation methods and means will continue to emerge, providing more options and possibilities for the fatigue life and reliability evaluation of Marine crankshaft forgings.
