Engineering design is an exploratory creative process, a process of analysis, synthesis, decision-making, evaluation and optimization according to certain goals. In this process, a series of design parameters and design variables such as load, displacement, stress, strength, stiffness and life are defined to describe many engineering things and provide a large number of numerical calculations for engineering design; in addition, mechanical principles The design of the plan, the formulation of the mechanical structure and structural modeling, the selection of materials, parameters and coefficients, and the determination of process procedures all require engineering and technical personnel to make inferences, reasoning and decisions based on experience and intelligence. When analyzing and designing a mechanical system, it is necessary to establish a mathematical model for the complex mechanical system that can be used for analysis and design. At this time, the complex mechanical system must be simplified or idealized, so that the simplified mathematical model and When compared with actual mechanical systems, there are often errors or uncertainties. If certain errors and uncertainties are ignored during the modeling of a mechanical system and are not included in the expected data, it is impossible for the designer to trust the analysis based on this model. and designs can be applied to actual mechanical systems.
Yra yra įvairios klaidos ir neapibrėžtumai in mašinos. Kai kurie parametrai turi gamyba klaidos, diegimas klaidos arba neapibrėžtumai; kai kurie parametrai turi skaičiavimo klaidos ir matavimas klaidos; kai kurios mechaninės sistemos turi skirtingos charakteristikos kai jie yra in skirtingos darbinės sąlygos. Parametras vertės; kai kurie parametrai turi a tikras parametras variacija diapazonas; kai kurie parametrai negali būti tiksliai išmatuota arba duota at at dabartis.
Beveik visi dizainas kintamieji nešiojimas a tam tikras laipsnis iš neapibrėžtumas, ir in in inžinerija analizė ir dizainas, jie gali būti padalinti į tris kategorijas pagal jų šaltinių:
(1) Fizinis neapibrėžtumas In inžinerija projektavimas, ten yra daug fiziniai kiekiai, toks as apkrova, medžiaga savybės, geometriniai matmenys, kad yra išsklaidyti. Tai tipas išsklaidytas Tai tipas ištikimybė kad yra tiesiogiai susiję su fiziniai kiekiai is paprastai vadinama neapibrėžtumu of physical quantities.
(2) Statistinis neapibrėžtumas The analysis of the distribution characteristics of variables and the determination of distribution functions are inneatable from statistics and judgment. Tačiau, any statistics and judgment are based samples of variables, and the capacity of any sample cannot be infinite. The distribution pattern of any variable is determined through statistics and inference. Todėl, the statistical method of any parametras yra neapibrėžtumas. Tai neapibrėžtumas sukelta pagal statistika is vadinama statistinė neapibrėžtumas.
(3) Neapibrėžtumas iš the model In engineering design and analysis, a model of the relationship between input quantities and output quantities must be established. The models are established based on mechanical principles or experience. Different models may be established for the same practical problem, and the models may be Certainty can also be uncertainty. Tačiau, in mechaninis projektavimas, mechaninės dalys arba sistemos are labai kompleksas, ir paprastas matematinis modeliai negali visiškai atspindėti faktinės struktūrinės sąlygos. Įvairios prielaidos padaryta on the model and supaprastinimas iš kompleksas ribos sąlygos valia priežastis modelis to yra neapibrėžtumas. Neapibrėžtumas a the model will have a great impact on the results of mechanical design analysis and should be paid enough attention to.
