Goodman Diagram

The rotor blades shall be of the tapered/twisted, free vortex, reaetion design (Figure 5-21). The blades shall be speeifieally designed for the dirty FCC flue gas applieation. Seller shall provide a Goodman Diagram for the highest stressed loeation... 

A Goodman Diagram shall be provided for tlie highest stressed loeation of the rotor blade at the normal (guarantee) point. 

Generalized compressibility charts. 17, 517-20 Goodman diagram, 251 Guide vanes, 148... 

Baseline Goodman diagram and relation between CLD and SN-curve... 

As was indicated, modification of the CLD is related to modification of the SN-curves. With a modification of the CLD, a modification is meant which does not involve any changes to the experimental SN-curves, which were used to construct the CLD. On the other hand, any SN-curves that are derived from the interpolation can be affected by the CLD-modification. In order to allocate more damage to the small amplitude cycles, some alternative CLDs have been proposed previously [32]. For example, in one alternative CLD the N=1 line is the same as in the linear Goodman diagram, but all other lines are drawn parallel to the N=1 line. In this case, the permissible number of cycles at a certain stress level and mean stress can be found for a lin-log SN-curve using ... 

The two formulations are the same in the region between R=-l and R=0.1 (straight lines between corresponding points on the projected SN-curves). Beyond R=0.1, two versions of an interpolation were used, the first reminiscent of the Goodman diagram, the second similar to the parallel lines-altemative. These formulations and the corresponding prediction results are displayed for log-log SN-curves in Fig. 12. 

From Figure 13.11, it can be seen that the allowable stress line and the shaft stress line can both be drawn on the modified Goodman diagram. 

A fatigue analysis was made to determine if the tie rods will fail due to fatigue in the unlikely event that the rod vibrates in resonance with the von Karman vortex frequency. The modified Goodman diagram was used in this analysis. This method is described in Reference 6. 

The modified Goodman diagram is shown in Figure 12-4. The values for Su, S, and Sae are given by Reference 6 for AISI 304 stainless steel at 600°F. The maximum alternating stress and mean stress values given above determine the location of point (1) in Figure 12-4. 

Fig. 7.46 Goodman diagram of 3Y-TZP for specimens tested for 10" cycles. Numbers next to the symbols indicate the number of specimens tested [17]. With kind permission of John Wiley and Sons...

One of the key limitations of the S-N curve is its inabUity to predict lifetimes at stress ratios different from those under which the curve was developed. To predict the lifetime of a certain component, a more useful presentation of fatigue life test data is the modified Goodman diagram. 

It is worth restoring the Goodman diagram concept to appreciate its use. Essentially, the emphasis of Goodman s work was on tensile-mean stress with respect to fatigue life. The stress required to produce failures during a specified number of cycles is directly related to tensile strength, as indicated schematically in Fig. 7.47. 

Fig. 8.22. Modified Goodman diagram showing fatigue stress amplitude required to cause failure in 10 cycles as a function of mean stress for two carbon-fibre reinforced epoxy resin materials (a) unidirectionally reinforced, stressed parallel to fibres, and (b) cross-plied laminate, with 45% of plies parallel to stress, and 55% transverse. Fibre volume fraction 60% (after R. Tetlow).

Figure 11.8 Modified Goodman diagram for fatigue strength of concrete subjected to compression with 2.10 cycles, after Neville (1997).

Therefore, as far as shear stress is concerned there is no negative quadrant in the Goodman diagram. Moreover, shear stress amphtude or the same fatigue limit Xf seem not to be influenced by a possible mean stress x , provided the maximum... 

Therefore, the Goodman line turns into a two line diagram ECB called modified Goodman diagram. Looking at Fig. 5.43 and Eq. (3.53) the new maximum... 

Fig. 5.46 Smith or Modified Goodman diagram for axial and bending fully reversed loads,...

Fig. 5.53 a Goodman diagram b S-N diagram in completely reversed torsion... 

Fig. 5.56 Modified Goodman diagram for a 40NiCrMo7steel shaft, 85 mm diameter, subjected to fully reversed traction, rotating bending an rotating torsion, respectively...

Derive the modified Goodman diagram of a NiCrMo, type 40NiCrMo7, 850 MPa yield strength and 45 % reduction of area RA, under... 

The modified Goodman diagram is, therefore, the one BMFGHLECB shown in Fig. 5.56. Moving to rotating bending. Table 3.3 of Sect. 3.6 provides the load factor Cid = 1.1 since the shaft is not thick, therefore... 

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