傅惠民 文歆磊 楊海峰
摘 要:產(chǎn)品壽命的不斷提高使得可靠性試驗(yàn)費(fèi)用大、時(shí)間長(zhǎng),工程上往往難以承受,同時(shí)隨著數(shù)字化設(shè)計(jì)、智能制造的快速發(fā)展,都對(duì)基于數(shù)字仿真的可靠性測(cè)試需求越來(lái)越迫切。但是可靠性仿真的可信性問(wèn)題長(zhǎng)期困擾著人們,為此,本文建立了一種可靠性仿真檢驗(yàn)方法,能夠以高置信水平判斷產(chǎn)品可靠度和可靠壽命的仿真是否正確。同時(shí),鑒于產(chǎn)品性能退化是其可靠性降低并逐步失效的主要原因,文中還給出性能退化曲線可靠性仿真的檢驗(yàn)方法,能夠以高置信水平判斷性能退化曲線在哪一時(shí)間段已被正確仿真,在哪一時(shí)間段尚未被正確模擬,為進(jìn)一步分析性能退化曲線未被正確仿真的原因提供指導(dǎo)。本文方法不但對(duì)正態(tài)分布、Weibull分布、極值分布、指數(shù)分布、二項(xiàng)分布等任意分布都適用,而且對(duì)完全數(shù)據(jù)、不完全數(shù)據(jù)和無(wú)失效數(shù)據(jù)等各種類型的數(shù)據(jù)也均適用。并且計(jì)算簡(jiǎn)單,便于工程應(yīng)用。
關(guān)鍵詞: 可靠性仿真;仿真檢驗(yàn);可靠度;壽命;性能退化;機(jī)電產(chǎn)品
【Abstract】 High cost and long duration of reliability experiment arisen by the improvement of product lifetime, as well as the rapid development of digital designing and intelligent manufacturing, lead to the urgent demand for reliability test based on digital simulation. To settle the credibility issue of simulation, a test method for reliability simulation is proposed in this paper to judge whether the reliability and reliable lifetime of product are simulated correctly with high confidence level. Considering the performance degradation is the main reason for product reliability reduction and even failure, a test method for reliability simulation of degradation curve is further presented, which can distinguish the correct simulated segment and the incorrect one with high confidence level. The proposed methodology is applicable to any distribution, as well as a wide variety of data including the complete failure data, incomplete data and zero-failure data. In addition, the easy calculation also makes it convenient for engineering application.
【Key words】 ?reliability simulation; simulation test; reliability; lifetime; performance degradation; mechanical and electrical products
0 引 言
仿真技術(shù)已成為理論分析和物理試驗(yàn)之后的第三大科學(xué)研究手段,特別是在當(dāng)前電子產(chǎn)品、機(jī)械產(chǎn)品、機(jī)電產(chǎn)品等壽命越來(lái)越長(zhǎng),可靠性試驗(yàn)費(fèi)用越來(lái)越高,以及數(shù)字化設(shè)計(jì)、智能制造快速發(fā)展的背景下,可靠性仿真發(fā)揮著越來(lái)越重要的作用[1-3]。另一方面,對(duì)于火星車、月球基地設(shè)備等在地面無(wú)法開展試驗(yàn)的研究對(duì)象,只能通過(guò)仿真對(duì)其壽命和可靠性進(jìn)行預(yù)測(cè)[4-5]。但是,仿真系統(tǒng)是否正確可信一直困擾著人們,如何對(duì)仿真系統(tǒng)進(jìn)行校核、驗(yàn)證和確認(rèn)(Verification, Validation and Accreditation, VV&A)至關(guān)重要[6-7]。在整個(gè)VV&A過(guò)程中,最關(guān)鍵的環(huán)節(jié)是通過(guò)建立科學(xué)合理的驗(yàn)證方法,判斷仿真系統(tǒng)與實(shí)際系統(tǒng)是否一致。工程上,通常選取若干個(gè)典型條件下的仿真結(jié)果與相同條件下的試驗(yàn)結(jié)果進(jìn)行對(duì)比檢驗(yàn),若二者無(wú)顯著性差異即可認(rèn)為仿真正確。文獻(xiàn)[8-11]給出了正態(tài)分布均值和方差、指數(shù)分布均值、二項(xiàng)分布參數(shù)等仿真結(jié)果的檢驗(yàn)方法。在實(shí)際應(yīng)用中,還常常遇到經(jīng)假設(shè)檢驗(yàn)仿真結(jié)果的均值和方差都無(wú)顯著差異,而可靠度和可靠壽命卻存在顯著差異的情況。文獻(xiàn)[12-14]通過(guò)引入母體特征值置信分布的概念,系統(tǒng)地建立了基于“大概率原則”的置信檢驗(yàn)理論。在此基礎(chǔ)上,本文進(jìn)一步建立可靠性仿真檢驗(yàn)方法,能夠?qū)θ我夥植枷碌目煽慷?、可靠壽命和可靠性退化曲線的仿真結(jié)果進(jìn)行檢驗(yàn)。
1 可靠度仿真檢驗(yàn)方法
設(shè)R為產(chǎn)品在t時(shí)刻的可靠度,R*為通過(guò)仿真得到的產(chǎn)品在t時(shí)刻的可靠度。由于R是未知的,所以無(wú)法直接判斷R*與R是否相等,亦即無(wú)法判斷該可靠度仿真是否正確。下面給出一種統(tǒng)計(jì)學(xué)意義下的可靠度仿真檢驗(yàn)方法。
6 結(jié)束語(yǔ)
(1)建立了可靠性仿真檢驗(yàn)方法,能夠以高置信水平判斷產(chǎn)品可靠度、可靠壽命和可靠性退化曲線的仿真是否正確。
(2)本文方法不僅對(duì)正態(tài)分布、Weibull分布、極值分布、指數(shù)分布、二項(xiàng)分布等任意分布都適用,而且對(duì)完全數(shù)據(jù)、不完全數(shù)據(jù)和無(wú)失效數(shù)據(jù)等各種類型的數(shù)據(jù)也均適用。
(3)本文方法對(duì)電子、機(jī)械等各類產(chǎn)品和系統(tǒng)均適用,并且可用小樣本進(jìn)行檢驗(yàn),計(jì)算簡(jiǎn)單,便于工程應(yīng)用。
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