1、 FORD LABORATORY TEST METHODBA 157-01Date Action Revisions 2006 05 25 Activated D. Saathoff Printed copies are uncontrolled Copyright 2006, Ford Global Technologies, LLC Page 1 of 27 SELF-PIERCE RIVETING SCHEDULE DEVELOPMENT ACCEPTANCE TEST FOR ALUMINUM UNCOATED AND COATED LOW CARBON STEEL SHEET App
2、lication This procedure defines the self-pierce riveting acceptance test for rivet schedule development for aluminum, uncoated and coated low carbon steel sheet. All such sheet material must pass minimum performance testing. Consult the appropriate Engineering Material Specification for material exc
3、eptions. Testing confirms that the correct rivet and die combination were used to satisfactorily join a given gauge of sheet metal together. Cross sections of the rivet joint must be evaluated to insure a robust rivet joint. After the correct tooling has been identified lap-shear and T-peel samples
4、are built. Initial testing requires a sample size of 30 each for the strength tests. Samples are pulled on a tensile test machine. Apparatus Required Self-pierce riveting press This test shall be conducted on an appropriate hydraulic or servo driven single point press-type SPR pedestal riveting syst
5、em and, in general, complying with the Self-pierce Riveting Manufacturing requirements for size and type of machine required. It shall have preclamp and punch force capacities to meet the requirement of the range of material gauges to be tested. Flushness Gauge Digital Metric Dial Caliper Mitutoyo M
6、odel #ID-C1012EB or equivalent. Flushness Gauge (To calibrate the gauge place on a surface plate feet down and press the zero button) Self-piercing Rivet Ford standard design will be used for all tests. The rivet coating method and base material will be selected from Ford Manufacturing Standard, S90
7、0. Processing will follow Engineering Specification ES-5G1A-1B279-AA. FORD LABORATORY TEST METHODBA 157-01Printed copies are uncontrolled Copyright 2006, Ford Global Technologies, LLC Page 2 of 27 Preparation of Material The material for self-pierce riveting qualification shall be representative of
8、production practices in the ordered thickness. The material shall be sheared in 25X100 mm pieces free from burrs and prepared from the material under test. Care shall be exercised so as not to remove any oils or die lubrication used for stamping, corrosion or shipping protection. Coated Galvanized S
9、heet Material Coating thickness on each side of panels must meet required manufacturers specification for production intent. SPR C-frame Alignment The C-frame alignment should be checked before test samples are built. A properly manufactured C-frame will produce a uniform, symmetrically shaped, roun
10、d button. Alignment is checked by setting rivets in a coupon and evaluated by 2 cross sections taken inline and transverse through the rivet centerline. Ideal Self-Pierce Rivet (SPR) Metallographic Cross-sections Note: Gaps around the rivet barrel, leg cracking or buckling and coining conditions may
11、 cause premature fatigue failure. When fastening dissimilar materials, rivet tail breakthrough and radial button cracking may cause corrosion failures. FORD LABORATORY TEST METHODBA 157-01Printed copies are uncontrolled Copyright 2006, Ford Global Technologies, LLC Page 3 of 27 Determining Acceptabl
12、e Leg Flare Metallographic Cross-section Evaluation There are several significant joint characteristics and dimensions that must be assessed and measured by metallographic and optical microscopy techniques. The following dimensions shall be checked during metallographic examination/optical microscop
13、y: t min (mm) Remaining Material Thickness The thinnest part of the plastically deformed material on the die side. LL (mm) This value is the distance between the rivet leg tip and the tangential point of the rivet leg side to the lower material in the joint. This gives the Left Hand locking value. L
14、R (mm) This value is the distance between the rivet leg tip and the tangential point of the rivet leg side to the lower material in the joint. This gives the Right Hand locking value. Y (mm) Flushness This is a measure of flushness. With a countersunk rivet, ideally, the surface on the head should b
15、e flush with the top sheet of material. With a headed rivet the underside of the head should be flush up against the top sheet of material. T1 (mm) Material thickness bottom sheet T2 (mm) Material thickness top sheet Note: The cross section of a rivet joint should be free of any voids around the out
16、side of the barrel and or under the rivet head. Voids inside the barrel under the rivet head are acceptable when jointing HSLA materials. Button cap thickness (tmin) is determined in the destructive testing phase. If the cap remains attached to the parent sheet material and does not crack around the
17、 base of the rivet tail it is considered acceptable. FORD LABORATORY TEST METHODBA 157-01Printed copies are uncontrolled Copyright 2006, Ford Global Technologies, LLC Page 4 of 27 Sample preparation Samples must be assembled in a test fixture, which provides a 25mm overlap of the 25X100 mm test samp
18、les to eliminate testing errors. The fixture ensures that the rivet is installed in the center of the 25mm overlap consistently. FORD LABORATORY TEST METHODBA 157-01Printed copies are uncontrolled Copyright 2006, Ford Global Technologies, LLC Page 5 of 27 Sample Lap-shear Data Sample # Head Height P
19、eak Load (lbf) Energy (in-lbf) Failure Mode 1 +0.00 mm 792.1 206.8 Tearing of bottom material 2 +0.01 mm 772.1 197.6 Tearing of bottom material 3 +0.01 mm 790.7 248.5 Tearing of bottom material 4 +0.00 mm 789.3 248.3 Tearing of bottom material 5 -0.01 mm 800.9 230.8 Tearing of bottom material 6 +0.0
20、2 mm 794.4 211.2 Tearing of bottom material 7 +0.00 mm 789.0 215.2 Tearing of bottom material 8 +0.00 mm 762.2 204.1 Tearing of bottom material 9 +0.00 mm 768.6 226.5 Tearing of bottom material 10 +0.00 mm 772.3 229.5 Tearing of bottom material 11 -0.01 mm 772.0 206.8 Tearing of bottom material 12 -
21、0.01 mm 793.1 220.4 Tearing of bottom material 13 +0.00 mm 807.5 256.7 Tearing of bottom material 14 +0.00 mm 800.2 230.4 Tearing of bottom material 15 +0.00 mm 790.6 211.0 Tearing of bottom material 16 +0.00 mm 775.6 243.6 Tearing of bottom material 17 +0.02 mm 768.6 250.7 Tearing of bottom materia
22、l 18 +0.01 mm 801.2 214.8 Tearing of bottom material 19 +0.01 mm 779.1 212.5 Tearing of bottom material 20 +0.01 mm 799.0 212.8 Tearing of bottom material 21 +0.00 mm 798.0 207.7 Tearing of bottom material 22 +0.00 mm 792.2 211.2 Tearing of bottom material 23 +0.00 mm 761.7 200.7 Tearing of bottom m
23、aterial 24 +0.00 mm 740.3 186.7 Tearing of bottom material 25 +0.00 mm 761.9 207.5 Tearing of bottom material 26 +0.00 mm 781.0 204.9 Tearing of bottom material 27 +0.01 mm 766.2 223.9 Tearing of bottom material 28 +0.00 mm 769.4 200.5 Tearing of bottom material 29 +0.01 mm 769.2 191.0 Tearing of bo
24、ttom material 30 +0.00 mm 776.5 194.2 Tearing of bottom material Mean 781.2 216.9 Std. Dev. 15.78 18.52 Low 740.3 186.7 High 807.5 256.7 FORD LABORATORY TEST METHODBA 157-01Printed copies are uncontrolled Copyright 2006, Ford Global Technologies, LLC Page 6 of 27 Sample T-Peel Data Sample # Head Hei
25、ght Peak Load (lbf) Energy (in-lbf) Failure Mode 31 -0.02 mm 330.9 140.3 Tail pull-out 32 +0.00 mm 386.2 166.9 Tail pull-out 33 -0.01 mm 352.6 145.6 Tail pull-out 34 +0.00 mm 353.5 146.0 Tail pull-out 35 +0.00 mm 349.9 151.2 Tail pull-out 36 +0.02 mm 337.9 143.9 Tail pull-out 37 -0.01 mm 376.4 161.4
26、 Tail pull-out 38 +0.00 mm 336.6 148.0 Tail pull-out 39 -0.01 mm 349.2 145.2 Tail pull-out 40 +0.00 mm 333.6 145.6 Tail pull-out 41 +0.00 mm 294.3 121.4 Tail pull-out 42 +0.00 mm 342.9 146.6 Tail pull-out 43 +0.00 mm 345.8 149.5 Tail pull-out 44 +0.00 mm 329.7 137.7 Tail pull-out 45 -0.01 mm 321.9 1
27、38.1 Tail pull-out 46 -0.02 mm 375.4 149.3 Tail pull-out 47 -0.01 mm 335.4 141.0 Tail pull-out 48 +0.00 mm 326.4 140.8 Tail pull-out 49 +0.00 mm 331.6 143.6 Tail pull-out 50 -0.01 mm 363.2 146.4 Tail pull-out 51 +0.00 mm 314.3 142.1 Tail pull-out 52 -0.01 mm 324.1 142.2 Tail pull-out 53 +0.00 mm 336
28、.3 148.3 Tail pull-out 54 +0.00 mm 358.9 156.0 Tail pull-out 55 +0.00 mm 326.7 139.1 Tail pull-out 56 -0.01 mm 331.6 143.6 Tail pull-out 57 -0.01 mm 348.6 148.0 Tail pull-out 58 -0.02 mm 343.5 147.5 Tail pull-out 59 -0.01 mm 343.7 147.1 Tail pull-out 60 -0.02 mm 337.2 146.4 Tail pull-out Mean 341.3
29、145.6 Std. Dev. 18.89 7.776 Low 294.3 121.4 High 386.2 166.9 FORD LABORATORY TEST METHODBA 157-01Printed copies are uncontrolled Copyright 2006, Ford Global Technologies, LLC Page 7 of 27 Rivet Schedule Analysis The underlying assumption of the statistical tests used in this procedure requires the d
30、ata to be at least approximately normally distributed. Data should be analyzed for normality, stability and capability. If data is not found to be normal a transformation is required. To check for normality of data using Minitab 13, load data into the worksheet and pick, Stat Basic Statistics Displa
31、y Descriptive Statistics, then select output data from list. Then pick graphs and check the Graphical Summary box, then pick OK, OK to generate the graph below. 39037035033031029095% Confidence Interval for Mu35034534033595% Confidence Interval for MedianVariable: UTS T-peel (lbf) 332.05715.042334.2
32、24Maximum3rd QuartileMedian1st QuartileMinimumNKurtosisSkewnessVarianceStDevMeanP-Value:A-Squared:347.96025.391348.329386.200350.575337.550330.600294.300301.030550.258607356.74518.888341.2770.2530.45395% Confidence Interval for Median95% Confidence Interval for Sigma95% Confidence Interval for MuAnd
33、erson-Darling Normality TesDescriptive StatisticsDescriptive Statistics: UTS T-peel (lbf) Variable N Mean Median TrMean StDev SE Mean UTS T-pe 30 341.28 337.55 341.04 18.89 3.45 Variable Minimum Maximum Q1 Q3 UTS T-pe 294.30 386.20 330.60 350.58 The P-value in the graph table above is the number to
34、look at to evaluate the normality of the data. If the P-value is greater than 0.05 it is sufficient evidence to continue with standard statistical testing. If the StDev number is small as compared to the mean it is a good indicator of the stability and repeatability of the rivet schedule. Note: T-Pe
35、el data is analyzed first because it is more sensitive to variations and will first indicate any instability in the rivet schedule FORD LABORATORY TEST METHODBA 157-01Printed copies are uncontrolled Copyright 2006, Ford Global Technologies, LLC Page 8 of 27 Rivet Schedule Analysis (Stability of proc
36、ess) Next check to see if the data collected are representative of a stable, in control process and therefore predictable. Plotting bar charts with Excel of the T-peel and Lap-shear strength data will give you an indication of the variability of the rivet schedule. If low UTS outliers are prevalent
37、in the T-peel data bar chart, additional work may be required to meet strength requirements. Final strength numbers to be used for evaluation are equal to the mean 3 StDev. Additional evaluation for normality and stability of the data can be obtained by using I-MR Charts and Descriptive Statistics G
38、raphs found in Minitab 13. To generate the graph below, load data into worksheet then, pick Stat Quality tools Capability six-pack (normal), Select UTS(lbf) for the response variable (Y) and group size 1, pick tests and check box Perform all eight tests, click Ok, then input upper and lower specific
39、ation, click Ok. 3020100410360310260Indiv idual and MR ChartObser.IndividualValueMean=341.3UCL=398.6LCL= 283.97550250Mov.RangeR=21.56UCL=70.45LCL= 0302010Last 25 Observations375350325300Observation NumberValues480225Capability PlotProcess ToleranceIIIIIIIISpecificationsWithinOverall380340300Normal P
40、rob Plot400350300Capability HistogramWithinStDev:Cp:Cpk:19.11532.592.36OverallStDev:Pp:Ppk:19.05122.602.37T-Peel Capibility AnalysisFORD LABORATORY TEST METHODBA 157-01Printed copies are uncontrolled Copyright 2006, Ford Global Technologies, LLC Page 9 of 27 Rivet Schedule Analysis Validity of testi
41、ng requires that data be normal. To check normality of data using Minitab 13, load data into the worksheet and pick, Stat Basic Statistics Display Descriptive Statistics, then select output data from list. Then pick graphs and check the Graphical summary box, then pick Ok, OK to generate the graph b
42、elow. 740 760 780 80095% Confidence Interval for Mu772 782 79295% Confidence Interval for MedianVariable: UTS (lbf)Lap-Shear StudyA-Squared:P-Value:MeanStDevVarianceSkewnessKurtosisNMinimum1st QuartileMedian3rd QuartileMaximum775.27312.564772.0230.5930.113781.16315.776248.876-4.0E-01-2.1E-0130740.30
43、0769.050780.050793.425807.500787.05421.208791.780Anderson-Darling Normality Test95% Confidence Interval for Mu95% Confidence Interval for Sigma95% Confidence Interval for MedianDescriptive StatisticsDescriptive Statistics: Peak Load (lbf) Variable N Mean Median TrMean StDev SE Mean Peak Load 30 781.
44、16 780.05 781.70 15.78 2.88 Variable Minimum Maximum Q1 Q3 Peak Load 740.30 807.50 769.05 793.43 The P-value in the graph table above is the number to look at to evaluate the normality of the data. If the P-value is greater than 0.05 it is sufficient evidence to continue with standard statistical te
45、sting. If the StDev number is small as compared to the mean it is a good indicator of the stability and repeatability of the rivet schedule. FORD LABORATORY TEST METHODBA 157-01Printed copies are uncontrolled Copyright 2006, Ford Global Technologies, LLC Page 10 of 27 Rivet Schedule Analysis Plottin
46、g bar charts with Excel of the Lap-shear strength data will give you an indication of the variability of the rivet schedule. If low UTS outliers are prevalent, additional work to the rivet schedule may be required to meet strength requirements. Final strength numbers to be used for evaluation are eq
47、ual to the mean 3 StDev. To generate the graph below, load data into Minitab 13 worksheet then, pick Stat Quality tools Capability six-pack (normal), Select UTS(lbf) for the response variable (Y) and group size 1, pick tests and check the Perform all eight tests box, click Ok, then input upper and l
48、ower specification, click Ok. 0 102030260310360410Individual and MR ChartObser.IndividualValueMean=341.3UCL=398.6LCL=283.90255075Mov.RangeR=21.56UCL=70.45LCL=010 20 30Last 25 Observations300325350375Observation NumberValues225 440Capability PlotProcess ToleranceIIIIIISpecificationsWithinOverall300 3
49、40 380Normal Prob Plot300 350 400Capability HistogramWithinStDev :Cp:Cpk:19.11531.871.72Ov erallStDev :Pp:Ppk:19.05121.881.73Lap-Shear AnalysisFORD LABORATORY TEST METHODBA 157-01Printed copies are uncontrolled Copyright 2006, Ford Global Technologies, LLC Page 11 of 27 Tooling Performance Sample Normal Capability Flushness Analysis Plots for Lap-shear coupons are used to evaluate the equipment performance and process stability of the rivet schedule. Load data sample sets on Minitab 13 then, using Minitab 13 select: StatQuality ToolsCapability Analysis (Normal)
