Study On Calculating Method And Software Development Of The Key Members Of Reciprocatingmachinein In Fatigue And Fracture

Reciprocating machine was wildly useed in our lives. Some key members of reciprocating machine are complex and important, such as crankshaft, cylinder liner and cylinder block, connecting rod and piston rob, which are usually employed in various types of piston compressors, tanks, cars, tractors, locomotives and shipboard-type oil engines. And a great number of machine mentioned above are all acted undergone to many-stage or random loading, so the failure of these is very common. The accidents caused by fracture of these components are common affair in engineering.In this paper, the fatigue and fracture moldel of these key members of reciprocating machine was researched. A number of calculating formulas ware gave to resolve the traditional mechanics calculation and modern mechanics calculation of these components, including crankshaft, cylinder liner and cylinder block, connecting rod and piston rob. Software based on C++ Builder6.0 was developed, which can be used to analyse the strength and life of these components. This software has some remarkable characters, for example, it has stronger and faster calculating function, and it permits operater to choose stress calculation or stress intensity factor or life calculation flexibly. Further more, it can complete the work which can't be done by manual. A database based on MS SQL Server2000 was built, which include the traditional mechanical property data and the modern mechanical property data of material was generally used in reciprocating machine. It provides more than one hundred kinds of material's traditional mechanical property data and more than thirty kinds of material's modern mechanical property data. All of this is enough for the calculation of material was commonly used. Also these data can be added and modified with the increase of material's mechanical property data. Throught some examples, expecially the calculating and analyse for a cylinder block of a piston compressor that was imported from America by NCIC (Sinopec NanJing Chemical Industrial Co. LTD), the availability of the calculating model was proved and practicability of the software was tested. The result showed that the analyse and calculation of crankshaft and cylinder acted undergone to many-stage loading and subjected to complex stress states can be done well.On the basis of study, the author regards that research on calculating method and software development about key members of reciprocating machine in fatigue and fracture is valuable. It can be used to the design, operation management and safety analysis of these components.