1、 FORD LABORATORY TEST METHOD BA 115-01 Date Action Revisions Rev. 1 2013 12 09 Revised See Summary of Revisions A. Freis, NA 2013 05 30 Released A. Freis, NA Controlled document at www.MATS Copyright 2013, Ford Global Technologies, LLC Page 1 of 14 FLOW DRILL SCREW SCHEDULE DEVELOPMENT ACCEPTANCE TE
2、ST FOR ALUMINUM, LOW CARBON STEEL SHEET AND EXTRUSIONS Application This procedure defines the acceptance test for Flow Drill Screw (FDS) schedule development for aluminum, low carbon steel sheet and extrusions. All such sheet material must pass minimum performance testing. Consult the appropriate En
3、gineering Material Specification for material exceptions. Testing confirms that the correct screw and processing parameters were used to satisfactorily join materials together. Cross sections of the FDS joint must be evaluated to insure a robust joint. After the correct tooling has been identified,
4、lap shear and coach peel samples are fabricated. Initial testing requires a sample size of 30 each for the strength tests. Samples are pulled on a tensile test machine. Apparatus Required FDS Tooling This test shall be conducted on an appropriate servo driven FDS system and, in general, complying wi
5、th the FDS Manufacturing requirements for size and type of machine required. It shall have preclamp, insertion force and torque capacities to meet the requirement of the range of material gauges to be tested. FDS Ford standard design will be used for all tests. The base material will be selected fro
6、m Ford Manufacturing Standard, S900. Processing will follow Engineering Specification ESBU5A-1B318-AA. Preparation of Material The material for FDS qualification shall be representative of production practices in the ordered thickness. The material shall be sheared in 25 mm x100 mm pieces and free f
7、rom burrs and slivers. Care shall be exercised so as not to remove any oils or die lubrication used for stamping, corrosion or shipping protection. The rolling or extrusion direction of the material should be parallel to the 100 mm dimension. Coated Galvanized Sheet Material Coating thickness on eac
8、h side of panels must meet required manufacturers specification for production intent. Metallographic Cross-section Evaluation There are several significant joint characteristics and dimensions that must be assessed by metallographic and optical microscopy techniques. FORD LABORATORY TEST METHOD BA
9、115-01 Copyright 2013, Ford Global Technologies, LLC Page 2 of14 Figure 1: Cross section of FDS Figure 1 displays a cross section for a flow drill screw joints. The following characteristics shall be checked during metallographic examination/optical microscopy: Screw Seated The integrated washer sha
10、ll be fully seated on the top sheet of material. There should be no gaps between the underside of the screw washer and the top sheet. Threads Engaged The number of fully engaged threads shall be counted. A thread is considered engaged if the female thread is fully formed in the substrate material. P
11、artially formed threads are not counted in the engaged thread count. Rolling Threads The fastener rolling threads should extend through the joint past the bushing on the back side of the joint. Cracks in Stack There should be no cracks present in the layers of material. Cracked Screw The screw shoul
12、d not show any cracks or voids. Gaps in Stack Ideally no gaps should be present, however if gaps are in the stacks they should not extend out beyond the diameter of the screw head and integrated washer. Any gaps should be measured and quantified by the maximum height and width. Sample Preparation Sa
13、mples must be assembled in a test fixture, which provides a 25 mm overlap of the 25 mm x100 mm lap shear test samples to eliminate testing errors. The fixture ensures that the FDS is installed in the center of the 25 mm overlap consistently. The same fixture can be used for the coach peel samples by
14、 stacking the coupons on top of one another. A vice should be machined to accommodate the tip of the FDS when the peel samples are being bent with a 25 mm flat. Figure 2 shows the fixture used to make the FDS samples. FORD LABORATORY TEST METHOD BA 115-01 Copyright 2013, Ford Global Technologies, LL
15、C Page 3 of14 Figure 2: Sample Preparation Fixture (Side, Arial, End Views from left to right) Figure 3: Coach Peel Coupon Bending Fixture Machined hole in vice for screw clearance (head and tip) Coupons place in sample holder FORD LABORATORY TEST METHOD BA 115-01 Copyright 2013, Ford Global Technol
16、ogies, LLC Page 4 of14 Figure 4. Coach Peel Coupon Bending Fixture Statistical Analysis (Repeatability of Joint) The statistical analysis is comprised of 30 lap shear samples, 30 coach peel samples, and one sample comprising of a cross section and bushing for imaging. The samples are assembled using
17、 the coupon holder described above. While making the samples, the tightening torque is recorded as it will be used as an input for PV testing. Once the samples have been made they are tensile tested at 10 mm/min and the failure modes for each sample should be identified. Photographs of the failure m
18、odes should be taken. Below is an example of a set of the FDS data. Cycle time data should also be recorded at this time for future analysis. Table 1: Sample Lap Shear Data Sample # Tightening Torque (Nm) Peak Load (N) Failure Mode 1 9.05 7098 Tearing of top material 2 9.00 7027 Tearing of top mater
19、ial 3 9.01 6994 Tearing of top material 4 9.04 6974 Tearing of top material 5 9.00 6908 Tearing of top material 6 9.04 7079 Tearing of top material 7 9.02 6755 Tearing of top material 8 9.02 6989 Tearing of top material 9 9.02 6925 Tearing of top material 10 9.00 7013 Tearing of top material 11 9.05
20、 6847 Tearing of top material 12 9.05 7154 Tearing of top material 13 9.02 7111 Tearing of top material 14 9.04 6912 Tearing of top material 15 9.04 7031 Tearing of top material 16 9.02 7003 Tearing of top material 17 9.02 6964 Tearing of top material 18 9.02 6878 Tearing of top material 19 9.00 700
21、5 Tearing of top material 20 9.05 7163 Tearing of top material 21 9.02 7047 Tearing of top material Peel samples bent with a 25 mm flat 6mm radius on vice FORD LABORATORY TEST METHOD BA 115-01 Copyright 2013, Ford Global Technologies, LLC Page 5 of14 22 9.02 6940 Tearing of top material 23 9.02 7073
22、 Tearing of top material 24 9.00 7144 Tearing of top material 25 9.05 7035 Tearing of top material 26 9.05 7076 Tearing of top material 27 9.02 6911 Tearing of top material 28 9.04 7096 Tearing of top material 29 9.04 6883 Tearing of top material 30 9.02 6995 Tearing of top material Mean 7001 Std. D
23、ev. 96.90 Min. 6755 Max. 7163 Table 2: Sample Coach Peel Data Sample # Tightening Torque (Nm) Peak Load (N) Failure Mode 1 9.05 907 Tearing of top material 2 9.02 935 Tearing of top material 3 9.02 919 Tearing of top material 4 9.02 897 Tearing of top material 5 9.00 888 Tearing of top material 6 9.
24、05 924 Tearing of top material 7 9.05 891 Tearing of top material 8 9.02 935 Tearing of top material 9 9.04 912 Tearing of top material 10 9.04 902 Tearing of top material 11 9.02 925 Tearing of top material 12 9.05 947 Tearing of top material 13 9.05 951 Tearing of top material 14 9.02 936 Tearing
25、of top material 15 9.02 922 Tearing of top material 16 9.02 912 Tearing of top material 17 9.00 932 Tearing of top material 18 9.05 917 Tearing of top material 19 9.05 918 Tearing of top material 20 9.02 912 Tearing of top material 21 9.05 923 Tearing of top material 22 9.02 957 Tearing of top mater
26、ial 23 9.02 932 Tearing of top material 24 9.02 924 Tearing of top material 25 9.00 930 Tearing of top material 26 9.05 925 Tearing of top material 27 9.05 931 Tearing of top material 28 9.02 911 Tearing of top material 29 9.04 921 Tearing of top material 30 9.04 919 Tearing of top material Mean 922
27、 Std. Dev. 16.0 Min. 888 Max. 957 FORD LABORATORY TEST METHOD BA 115-01 Copyright 2013, Ford Global Technologies, LLC Page 6 of14 FDS Schedule Analysis Data should be analyzed for normality, stability, and capability. If data are not found to be normal a transformation may be required. This should b
28、e evaluated on a case by case. Please contact your local statistical subject matter expert for further direction. To check for normality of lap shear and coach peel peak load data using Minitab 15, load data into the worksheet and pick Stat Basic Statistics Graphical Summary, then select output data
29、 from the list. Then pick OK to generate the graph below. 960940920900MedianMean930.0927.5925.0922.5920.0917.5915.01st Quartile 912.00Median 922.503rd Quartile 932.00Maximum 957.00915.85 927.82917.23 928.8612.76 21.54A-Squared 0.27P-Value 0.640Mean 921.83StDev 16.02Variance 256.70Skewness -0.032419K
30、urtosis 0.285847N 30Minimum 888.00Anderson-Darling Normality Test95% Confidence Interval for Mean95% Confidence Interval for Median95% Confidence Interval for StDev95% Confidence IntervalsSummary for Peel Peak LoadFigure 5. Example Coach Peel Graph for Peak Load Descriptive Statistics: Peel Peak Loa
31、d (N) Figure 5 is an example graph output which includes the Anderson-Darling Normality Test. If the P-value is greater than 0.05 the data can be assumed to be normal. If the “StDev” number is small as compared to the mean it is a good indicator of the stability and repeatability of the FDS schedule
32、. Below is an example of cycle time data analysis (Figure 6). This data can be used to help insure that the production intent line has sufficient cycle time for each joint. The time is a Home to Home cycle with no feeding or movement time included. Table 3: Sample Cycle Time Data Cycle Time Sample #
33、 Shear Sample Peel Sample 1 3.64 3.54 2 3.58 3.61 3 3.64 3.61 4 3.68 3.69 5 3.63 3.64 6 3.59 3.71 7 3.60 3.63 8 3.65 3.54 9 3.60 3.64 10 3.59 3.61 11 3.66 3.70 12 3.64 3.69 13 3.60 3.64 14 3.56 3.60 15 3.64 3.52 16 3.60 3.75 FORD LABORATORY TEST METHOD BA 115-01 Copyright 2013, Ford Global Technolog
34、ies, LLC Page 7 of14 17 3.56 3.58 18 3.63 4.41 19 3.70 3.61 20 3.52 3.61 21 3.60 3.61 22 3.60 3.64 23 3.59 3.56 24 3.71 3.55 25 3.53 3.67 26 3.51 3.56 27 3.53 3.60 28 3.53 3.65 29 3.55 3.68 30 3.57 3.60 3.083.043.002.962.92MedianMean3.013.002.992.982.972.961st Quartile 2.9500Median 2.99003rd Quartil
35、e 3.0300Maximum 3.08002.9747 2.99902.9600 3.01000.0399 0.0574A-Squared 1.03P-Value 0.010Mean 2.9868StDev 0.0471Variance 0.0022Skewness 0.19079Kurtosis -1.11756N 60Minimum 2.9100Anderson-Darling Normality Test95% Confidence Interval for Mean95% Confidence Interval for Median95% Confidence Interval fo
36、r StDev95% Confidence IntervalsSummary for Cycle Time (s)Figure 6. Example Output Graph for Cycle Time During design validation data must be collected from the lap shear and coach peel samples. The tightening torque should be recorded to analyze the process capability; an example value is illustrate
37、d on Figure 7 and is denoted as #6 on the graph. These data can be recorded in a table and should be analyzed with the stripping torque data for process capability. The FDS equipment should be used to collect the tightening torque data. FORD LABORATORY TEST METHOD BA 115-01 Copyright 2013, Ford Glob
38、al Technologies, LLC Page 8 of14 Figure 7. Torque vs. Time curve for FDS Process Table 4: Sample Tightening Torque Data Tightening Torque Value Sample # Shear Sample Peel Sample 1 8.03 8.07 2 8.03 8.03 3 8.01 8.05 4 8.05 8.03 5 8.07 8.01 6 8.03 8.01 7 8.03 8.05 8 8.03 8.01 9 8.01 8.03 10 8.07 8.03 1
39、1 8.03 8.01 12 8.01 8.07 13 8.01 8.03 14 8.01 8.03 15 8.03 8.01 16 8.05 8.05 17 8.03 8.01 18 8.01 8.05 19 8.03 8.01 20 8.05 8.01 21 8.01 8.05 22 8.01 8.01 23 8.01 8.05 24 8.09 8.01 25 8.03 8.05 26 8.05 8.01 27 8.03 8.01 28 8.01 8.03 29 8.03 8.01 30 8.03 8.07 The rolling torque and stripping torque d
40、ata should be analyzed for normality, stability, and capability. If the data are not found to be normal a transformation may be required. This should be evaluated on a case by case. Please contact your local statistical subject matter expert for further direction. To check for normality of lap shear
41、 and coach peel peak load data using Minitab 15, load data into the worksheet and pick Stat Basic Statistics FORD LABORATORY TEST METHOD BA 115-01 Copyright 2013, Ford Global Technologies, LLC Page 9 of14 Graphical Summary, then select output data from the list. Then pick OK to generate the graph be
42、low. See Figure 8. Figure 8. Example Coach Peel Graph for Peak Load Statistical Analysis (Process Capability) To understand the process capability 30 samples must be tested to stripping torque. The data for stripping torque, denoted by #7 and rolling torque, denoted by #5 in Figure 7 must be recorde
43、d and analyzed. This data should be collected using the FDS controller. See example data below. Table 5: Sample Rolling and Stripping Torque Data Stripped Samples Sample Rolling Torque (Nm) Stripping Torque (Nm) 1 2.32 15.78 2 2.383 11.89 3 2.383 13.11 4 2.109 14.14 5 2.598 14.14 6 1.797 11.19 7 2.8
44、71 15.13 8 2.188 16.70 9 1.914 11.07 10 2.188 15.29 11 2.227 16.52 12 2.422 15.45 13 2.520 12.23 14 2.012 17.42 15 2.168 20 + 16 2.070 16.8 17 2.070 16.93 18 2.266 17.25 19 1.992 17.50 20 2.539 13.18 21 2.559 18.07 22 2.734 16.99 23 2.188 15.04 24 2.070 20 + 25 2.285 20+ 26 1.816 20+ 8.058.048.038.0
45、28.01MedianMean8.0308.0258.0208.0158.0101st Quartile 8.0100Median 8.03003rd Quartile 8.0300Maximum 8.05008.0211 8.02898.0100 8.03000.0127 0.0183A-Squared 5.32P-Value Basic Statistics Graphical Summary, then select output data from the list. Then pick OK to generate the graph below. This should be co
46、mpleted for both rolling torque and stripping torque data, Figure 9 and 10. Figure 9. Example Coach Peel Graph for Peak Load Figure 10. Example Coach Peel Graph for Peak Load To understand the process capability, the upper and lower bounds for the set installation torque need to be determined. These
47、 numbers can be calculated from the rolling and stripping torque. The lower bound is 16.815.614.413.212.0MedianMean15.515.014.514.013.51st Quartile 13.495Median 14.6903rd Quartile 16.008Maximum 17.36014.212 15.32813.784 15.7111.190 2.009A-Squared 0.43P-Value 0.281Mean 14.770StDev 1.494Variance 2.233
48、Skewness 0.16152Kurtosis -1.11148N 30Minimum 12.150Anderson-Darling Normality Test95% Confidence Interval for Mean95% Confidence Interval for Median95% Confidence Interval for StDev95% Confidence IntervalsSummary for Stripping Toque1.81.61.41.21.0MedianMean1.501.481.461.441.421.401.381st Quartile 1.
49、3575Median 1.44003rd Quartile 1.5200Maximum 1.77001.3764 1.48961.3846 1.49540.1208 0.2038A-Squared 0.35P-Value 0.451Mean 1.4330StDev 0.1516Variance 0.0230Skewness -0.34311Kurtosis 1.20110N 30Minimum 1.0300Anderson-Darling Normality Test95% Confidence Interval for Mean95% Confidence Interval for Median95% Confidence Interval for StDev95% Confidence IntervalsSummary for Rolling ToqueFORD LABORATORY TEST METHOD BA 115-01 Copyright 2013, Ford Global Technologies, LLC Page 11 of14 calculated using the average rolling torque (r). The standa
