汽车排气管总成疲劳试验系统

汽车排气管总成疲劳试验系统 
The test sequence and the test extent are determined in the following:
• Test testing covers six samples that are subject to dynamic test and one sample that is
subject to temperature measurement.
• The converters are prepared with flanges welded on (see Figure 2)
• Manufacturing of a clamping device in order to apply load in axial direction on the
converters according to Figure 2.
• Assessment of the difference between the acceleration at the control sensor position and
on the center of the converters surface and assessment of lateral oscillations (see 4.2).
• On one converter five thermocouples are to be applied according to Figure 3. The
converter is heated at the respective temperature over one hour. After reaching a steady
state the surface temperatures T0 to T4 and the exhaust temperature TA are measured.
• For measuring the displacement of the substrate prior to test, on each intermediate check
and after finishing the test the length between the flanges and the substrate (l1 and l2)
and the total length (ltotal) are checked (see Fig. 3). The lengths l1 and l2 are to be
measured in the center of the substrate.
• Mode of failure is a displacement of the substrate higher than 3,0 mm or a frequency
difference of +1,5 Hz respectively -1,5 Hz.