From: Arthur W. Brooks Sent: Monday, May 05, 2008 8:11 AM To: Michael R. Kalish Subject: RE: early cut at FDR Slides Mike, My interpretation of the design criteria is that CD+EM under the category of "Total primary plus secondary stress" which "shall not exceed 3.0 KSm" (see excerpt below). The local high values for "node" stresses fall into the category of "Peak Stress" for which a fatigue evaluation may be required. Even here, I would argue that the node stress is very conservative. Typically a local averaged value is used (ie the element average stress). Also, technically the 0.5T cases is a GRD requirement (even though the trim coils currents that would go with it are probably zero). It's probably best to show we can handled it with some margin - Mike Z will inevitably want to be able to run a 0.5T TF with other coils though we don't have a realistic case in hand - the "iota=0.19" case is the closest. Your presentation is shaping up nicely (as always) Art --------------------------- 2.4.1.4 Stress Allowable Limit The Tresca stress resulting from the load combinations defined in Section2.2 shall not exceed the limits described in the following paragraphs: 2.4.1.4.1 Basic Stress Limits Based on elastic stress analyses, the following stress limits shall be met: • General primary membrane stress shall not exceed 1.0 KSm • Local primary membrane stress shall not exceed 1.5 KSm • Primary membrane plus bending stresses shall not exceed 1.5 KSm • Total primary plus secondary stress shall not exceed 3.0 KSm ----------------------------- 2.3.1.3 Peak Stress (F) Peak stress is that increment of stress which is additive to the primary plus secondary stresses due to local discontinuity or local thermal stress, including the effects of stress concentrations. A peak stress does not cause any noticeable distortion but is a possible source of a fatigue crack or a fracture. Examples of peak stresses are: • Surface stresses produced by thermal shock • Stress concentration at local structural discontinuity ------------------------------- -----Original Message----- From: Michael R. Kalish Sent: Sunday, May 04, 2008 1:58 PM To: Arthur W. Brooks Subject: early cut at FDR Slides Art, See what you think of what I've got......... not nearly done yet (old stuff mixed in with new stuff and sections not done) but tell me if I'm misinterpreting your analysis. I never really resolved what an allowable is for CD+EM can I use your average as opposed to nodal stress values? I need to understand again how realistic the nodal value is as opposed to the average stress value. We can add more weld locally if we have to.... I also need to figure allowables for SS at temp.........I'm done for today ... catch ya Monday Thanks again, If I had to figure this all out Monday along with everything else I would have been up very late Mike -----Original Message----- From: Arthur W. Brooks Sent: Saturday, May 03, 2008 2:26 PM To: Michael R. Kalish Subject: More on Trim Coils Stress Analysis Data Mike, I added some plots to the attached file. I ran two other EM only scenarios - 0.5T TF which also showed 80#/in and the 2T HB at t=0.197s which has been the worse case for Modular Coil Analysis. The 2T has a lower running load (50#/in) and the stresses are indeed lower. The 0.5T TF however shows larger stresses than the iota=0.19 case which also had 80#/in (see comparison table on last slide). The reported high stress are still very localized, peaking at the end of the welds. Art -----Original Message----- From: Arthur W. Brooks Sent: Saturday, May 03, 2008 1:32 PM To: Michael R. Kalish Subject: Trim Coils Stress Analysis Data Mike, Attached are results of the analyses to date. There is probably more than you want but I'm attached everything I have to let you pick and choose. I had started running some cases with just a single representative Coil (#1) to understand the various load case combinations (EM only, Cool down only, and EM+CD) and also whether friction mattered or not. You may be more interested in just the last set of runs with all the coils and mu=0.3 for the three load combinations. There are all run with the worse case identified from the GRD and Mike Z's added iota scan cases which is a high TF case: iota M1 M2 M3 PF4 PF5 PF6 TF 0.19 517.9 523.8 448.4 80.70 3.30 -5.779 164.1 There is a summary table at the end of the stresses found in the plots. If anything is not clear, or you need something else let me know. Art