请问谁知道Halt的随机振动怎么算加速因子 可靠性技术 新手提问 10年1月26日 编辑 pif2216 取消关注 关注 私信 最近用Halt试验箱子做HASS测试,目的是剔除缺陷产品;但想做的更多的,可找了很多资料都没有找到随机振动加速因子的计算方法; 哪位兄弟要知道,分享下,谢谢! 给TA打赏 共{{data.count}}人 人已打赏
forest_sheep lv4lv4 16年5月30日 [quote][url=pid=78195&ptid=8097]ice_fang发表于2010-7-1011:06[/url] Example:UsingtheVibrationmodel Problem: Estimatethetesttimetosimulate10yearsoflifei…[/quote] 第一次看见振动加速参数,学习了
justinbk lv4lv4 11年11月30日 可以参考一下MIL-std-810F。[b]回复[url=http://kekaoxing2011.host4.288idc.com/club/redirect.php?goto=findpost&pid=70107&ptid=8097]1#[/url][i]pif2216[/i][/b]
ice_fang lv3lv3 10年7月13日 DearAll, Sorry,mybossoncegivemeapaperliteraturewhichdescribevibrationmodel.SoIshareitwithall. Iquoteasectionforyourreference. InVibration,devicesaremountedonadynamicshakertableandsubjecttoeitherarandomorsinusoidal-typevibrationprofile.CommonrandomvibrationtestsaremostfrequentlyspecifiedintermsofPowerSpectralDensity(PSD)levels(seebelowFigure).FigureillustratesthepossiblePSDtestprofilelevelsrelatedtoasimilarparticularuseenvironment.ThePSDfunctiondescribesthedistributionofvibrationenergywithrespecttofrequency.TheamountoftimecompressionthatcanbeaccomplishedisrelatedtothePSDtestlevelanduselevel.Estimatesoftimecompressioncanbemadeoncetheuselevelestimateandspectraldensityprofileareestablished.Thetraditionalclassicaltime-compressionmodel(MIL-STD810E)isapowerlawmodel(seebelowFigure).Inapplyingthismodel,itisimportanttounderstandthefailuremechanismsince,inarandomvibration-loadingenvironment,theresonanceofthematerialcandominatethefatiguelife.Here,maximumvibrationamplitudesandstressoccur.However,fatiguefailuresarenotalwaysdominatedbythefundamentalresonancemode.Inpractice,manyofthestresspeaksintheuseenvironmentmayfallbelowthefatiguelimitofthematerial,whileotherswillbeabovethefatiguelimit.Itfollowsthatanacceleratedlifetestbaseduponthismodelshouldinherentlybeconservative.However,becausemostofthefatiguedamageoccursatthehigheststresspeaksinboththetestandinactualuse,thedegreeofconservatismisnotexcessive.AsnotedinbelowFigure,thePSDisinunitsofG2/Hz.ThesquareoftheGstresslevelattheresonancefrequencyisdirectlyproportionaltothePSDlevel(W~G2),sothemodelcanbeputintermsofeitherrandomorsinusoidal-resonanceG-stressloading.Inthemodel,thefatigueparameterisrelatedtoexperimentalslopeofthestresstocyclestofailuredata.Thisexponentvariesdependingonthefatiguelifeofthematerialsinvolved.Forexample,thevalueofb≈5iscommonlyusedforelectronicboards.However,conservativevalueforthefatigueparameterbisabout8(e.g.,Mb=4).MILSTD-810E(514.4-46)recommendsb=8forrandomloading.
pif2216A lv5lv5 10年7月12日 [b]回复[url=pid=78195&ptid=8097]7#[/url][i]ice_fang[/i][/b] 真的非常感谢你的分享!仔细看了下你分享的内容,有些问题还需要向你请教: 1)M_b=b/2wherebisthefatigueparameter这个参数怎么确定?比如你举的例子中AV=(WStress/WUse)Mb=(0.12/0.03)4=256的[b]4[/b]是怎么确定的? 2)G_f=resonantGsinusoidvibrationlevel怎么用的是正玄共振等级?不是随机振动么?正玄共振等级如何确定其值? 3)C=constant如何取值? 4)PSDLevel的值是实验根据具体产品得出还是共用的?比如 Level2:Avg.PSD=0.06G2/HZ(Content11GRMS) Level4:Avg.PSD=0.12G2/HZ(Content15.5GRMS) Level8:Avg.PSD=0.24G2/HZ(Content21.9GRMS) Level16:Avg.PSD=0.48G2/HZ(Content31GRMS) 还有你Level1PSD=0.03G2/HZ是推算的么?还是试验得出的? 5)最后一个问题,和楼上一个兄弟一样的,就是不知道兄弟这些公式和资料是出自什么文件上的阿?能共享下么? [b]真的再次感谢!!!!!!![/b]
ZICO863 lv5lv5 10年7月11日 [quote]A_V=T_Use/T_Stress=(W_Stress/W_Use)^(M_b) (W_Stress/W_Use)^(M_b)=(G_(f_Stress)/G_(f_Use))^(… ice_fang发表于2010-7-1010:56[url=pid=78194&ptid=8097][/url][/quote] 请教:该公式源于哪个标准或文献?
ice_fang lv3lv3 10年7月10日 Example:UsingtheVibrationmodel [b]Problem:[/b] Estimatethetesttimetosimulate10yearsoflifeinthefieldforanassembly thatistestedtoaLevel4PSDrandomvibrationtestcondition,shownin below[b]Remark[/b]description.Itisestimatedthattheassemblywillundergoaworst-caseLevel1- typerandomvibrationexposure1percentoftheassembly’slife.Therestof theassembly’slifeisrelativelybenignintermsofvibrationexposure. [b]Solution:[/b] First,usetheexpressionin[b]previousletter[/b]tofindthevibrationaccelerationfactor.SinceLevel4hasa PSDof0.12G2/Hz,thenLevel1is0.03G2/Hz. Therefore, AV=(WStress/WUse)Mb=(0.12/0.03)4=256. In10years,thedevicewillbeexposedtoaLevel1vibrationforabout87,600×0.01=876hours. Therefore,thenumberoftestcyclestosimulatethisis TStress=TUse/AV=876/256=3.5hours. [b]Remark:CommonrandomvibrationtestsaremostfrequentlyspecifiedintermsofPowerSpectralDensity(PSD)levels[/b] Level2:Avg.PSD=0.06G2/HZ(Content11GRMS) Level4:Avg.PSD=0.12G2/HZ(Content15.5GRMS) Level8:Avg.PSD=0.24G2/HZ(Content21.9GRMS) Level16:Avg.PSD=0.48G2/HZ(Content31GRMS)
ice_fang lv3lv3 10年7月10日 A_V=T_Use/T_Stress=(W_Stress/W_Use)^(M_b) (W_Stress/W_Use)^(M_b)=(G_(f_Stress)/G_(f_Use))^(2M_b) Ln(tf)=C-M_bLn(W) Where, A_V=vibrationaccelerationfactor T_Stress=vibrationduration T_Use=vibrationduration(nominal) W=randomvibrationinputPSDacross theresonancebandwidth(G2/Hz) W_StressisthePSDteststressand W_UsenominalusePSD G_f=resonantGsinusoidvibrationlevel M_b=b/2wherebisthefatigueparameter tf=timetofailure C=constant
adminM可靠性网管理员 lv6lv6 10年6月23日 [b]回复[url=pid=77134&ptid=8097]4#[/url][i]fuckit[/i][/b] 了解一下,希望有更多的高手如fuckit一样,来介绍介绍
adminM可靠性网管理员 lv6lv6 10年1月26日 没听过Halt试验中的随机振动计算加速因子 做HASS时,根据HALT试验得到的值,取一个百分比而已。 楼主可以再把问题描述清楚一些,为什么要计算随机振动的加速因子。目的是什么,以你的理解,大概如何计算????
很久前看过一本书,《可靠性强化试验理论与应用》,可能有这类问题的说明,你买本看看
能共享,公式所参考的文献吗
谢谢分享 ,具体出资哪里啊
[quote][url=pid=78195&ptid=8097]ice_fang发表于2010-7-1011:06[/url]
Example:UsingtheVibrationmodel
Problem:
Estimatethetesttimetosimulate10yearsoflifei…[/quote]
第一次看见振动加速参数,学习了
可以参考一下MIL-std-810F。[b]回复[url=http://kekaoxing2011.host4.288idc.com/club/redirect.php?goto=findpost&pid=70107&ptid=8097]1#[/url][i]pif2216[/i][/b]
楼上的应该是某家的试验数据吧~
小弟手边也有类似的数据
不过在IECorMIL标准上也没有这样的叙述
学习学习!
HALT模拟的振动模型与MIL-STD810E振动模型是相似的吗?
Thankssomuch!
DearAll,

Sorry,mybossoncegivemeapaperliteraturewhichdescribevibrationmodel.SoIshareitwithall.
Iquoteasectionforyourreference.
InVibration,devicesaremountedonadynamicshakertableandsubjecttoeitherarandomorsinusoidal-typevibrationprofile.CommonrandomvibrationtestsaremostfrequentlyspecifiedintermsofPowerSpectralDensity(PSD)levels(seebelowFigure).FigureillustratesthepossiblePSDtestprofilelevelsrelatedtoasimilarparticularuseenvironment.ThePSDfunctiondescribesthedistributionofvibrationenergywithrespecttofrequency.TheamountoftimecompressionthatcanbeaccomplishedisrelatedtothePSDtestlevelanduselevel.Estimatesoftimecompressioncanbemadeoncetheuselevelestimateandspectraldensityprofileareestablished.Thetraditionalclassicaltime-compressionmodel(MIL-STD810E)isapowerlawmodel(seebelowFigure).Inapplyingthismodel,itisimportanttounderstandthefailuremechanismsince,inarandomvibration-loadingenvironment,theresonanceofthematerialcandominatethefatiguelife.Here,maximumvibrationamplitudesandstressoccur.However,fatiguefailuresarenotalwaysdominatedbythefundamentalresonancemode.Inpractice,manyofthestresspeaksintheuseenvironmentmayfallbelowthefatiguelimitofthematerial,whileotherswillbeabovethefatiguelimit.Itfollowsthatanacceleratedlifetestbaseduponthismodelshouldinherentlybeconservative.However,becausemostofthefatiguedamageoccursatthehigheststresspeaksinboththetestandinactualuse,thedegreeofconservatismisnotexcessive.AsnotedinbelowFigure,thePSDisinunitsofG2/Hz.ThesquareoftheGstresslevelattheresonancefrequencyisdirectlyproportionaltothePSDlevel(W~G2),sothemodelcanbeputintermsofeitherrandomorsinusoidal-resonanceG-stressloading.Inthemodel,thefatigueparameterisrelatedtoexperimentalslopeofthestresstocyclestofailuredata.Thisexponentvariesdependingonthefatiguelifeofthematerialsinvolved.Forexample,thevalueofb≈5iscommonlyusedforelectronicboards.However,conservativevalueforthefatigueparameterbisabout8(e.g.,Mb=4).MILSTD-810E(514.4-46)recommendsb=8forrandomloading.
[b]回复[url=pid=78195&ptid=8097]7#[/url][i]ice_fang[/i][/b]
真的非常感谢你的分享!仔细看了下你分享的内容,有些问题还需要向你请教:
1)M_b=b/2wherebisthefatigueparameter这个参数怎么确定?比如你举的例子中AV=(WStress/WUse)Mb=(0.12/0.03)4=256的[b]4[/b]是怎么确定的?
2)G_f=resonantGsinusoidvibrationlevel怎么用的是正玄共振等级?不是随机振动么?正玄共振等级如何确定其值?
3)C=constant如何取值?
4)PSDLevel的值是实验根据具体产品得出还是共用的?比如
Level2:Avg.PSD=0.06G2/HZ(Content11GRMS)
Level4:Avg.PSD=0.12G2/HZ(Content15.5GRMS)
Level8:Avg.PSD=0.24G2/HZ(Content21.9GRMS)
Level16:Avg.PSD=0.48G2/HZ(Content31GRMS)
还有你Level1PSD=0.03G2/HZ是推算的么?还是试验得出的?
5)最后一个问题,和楼上一个兄弟一样的,就是不知道兄弟这些公式和资料是出自什么文件上的阿?能共享下么?
[b]真的再次感谢!!!!!!![/b]
[quote]A_V=T_Use/T_Stress=(W_Stress/W_Use)^(M_b)
(W_Stress/W_Use)^(M_b)=(G_(f_Stress)/G_(f_Use))^(…
ice_fang发表于2010-7-1010:56[url=pid=78194&ptid=8097][/url][/quote]
请教:该公式源于哪个标准或文献?
谢谢,学习了;有相关案例就更好了
Example:UsingtheVibrationmodel
[b]Problem:[/b]
Estimatethetesttimetosimulate10yearsoflifeinthefieldforanassembly
thatistestedtoaLevel4PSDrandomvibrationtestcondition,shownin
below[b]Remark[/b]description.Itisestimatedthattheassemblywillundergoaworst-caseLevel1-
typerandomvibrationexposure1percentoftheassembly’slife.Therestof
theassembly’slifeisrelativelybenignintermsofvibrationexposure.
[b]Solution:[/b]
First,usetheexpressionin[b]previousletter[/b]tofindthevibrationaccelerationfactor.SinceLevel4hasa
PSDof0.12G2/Hz,thenLevel1is0.03G2/Hz.
Therefore,
AV=(WStress/WUse)Mb=(0.12/0.03)4=256.
In10years,thedevicewillbeexposedtoaLevel1vibrationforabout87,600×0.01=876hours.
Therefore,thenumberoftestcyclestosimulatethisis
TStress=TUse/AV=876/256=3.5hours.
[b]Remark:CommonrandomvibrationtestsaremostfrequentlyspecifiedintermsofPowerSpectralDensity(PSD)levels[/b]
Level2:Avg.PSD=0.06G2/HZ(Content11GRMS)
Level4:Avg.PSD=0.12G2/HZ(Content15.5GRMS)
Level8:Avg.PSD=0.24G2/HZ(Content21.9GRMS)
Level16:Avg.PSD=0.48G2/HZ(Content31GRMS)
A_V=T_Use/T_Stress=(W_Stress/W_Use)^(M_b)
(W_Stress/W_Use)^(M_b)=(G_(f_Stress)/G_(f_Use))^(2M_b)
Ln(tf)=C-M_bLn(W)
Where,
A_V=vibrationaccelerationfactor
T_Stress=vibrationduration
T_Use=vibrationduration(nominal)
W=randomvibrationinputPSDacross
theresonancebandwidth(G2/Hz)
W_StressisthePSDteststressand
W_UsenominalusePSD
G_f=resonantGsinusoidvibrationlevel
M_b=b/2wherebisthefatigueparameter
tf=timetofailure
C=constant
[b]回复[url=pid=77134&ptid=8097]4#[/url][i]fuckit[/i][/b]
了解一下,希望有更多的高手如fuckit一样,来介绍介绍
忘记在哪里看到过的
振动的加速因子使用G值用逆幂模型(PowerLaw)进行计算的
有正常的振动的加速因子计算吗?????想交流一下
没听过Halt试验中的随机振动计算加速因子
做HASS时,根据HALT试验得到的值,取一个百分比而已。
楼主可以再把问题描述清楚一些,为什么要计算随机振动的加速因子。目的是什么,以你的理解,大概如何计算????