# \*TEMPERATURE, OP=NEW resets shell and beam temperatures to the initial values but keeps the last gradient (the shell stays bent, exit 0) **URL:** \ **Category:** Analysis issues\ **Created:** [October 21, 2026, 7:05pm UTC](https://calculix.discourse.group/t/temperature-op-new-resets-shell-and-beam-temperatures-to-the-initial-values-but-keeps-the-last-gradient-the-shell-stays-bent-exit-0/4213 "2026-10-21T19:05:57Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Sandervdb](https://avatars.discourse-cdn.com/v4/letter/s/49beb7/32.png) [@Sandervdb](https://calculix.discourse.group/u/Sandervdb)\ **Post date:** [October 21, 2026, 7:05pm UTC](https://calculix.discourse.group/t/temperature-op-new-resets-shell-and-beam-temperatures-to-the-initial-values-but-keeps-the-last-gradient-the-shell-stays-bent-exit-0/4213/1 "2026-10-21T19:05:58Z")
## Summary The manual, \*TEMPERATURE (section 7.132 of the 2.23 manual), says: “OP=NEW implies that the temperatures are reinitialised to the initial values.” For shells and beams the same card also carries the gradients (“For shell elements a temperature gradient can be defined in addition to a temperature”), and \*INITIAL CONDITIONS defines initial gradients (section 7.77). ccx resets the temperatures but keeps the gradients of the previous step. Test: a free S8R plate with initial temperature 0 (no gradient). Step 1 gives T = 20 with a gradient of 100: the plate stretches (U1 = 0.04 at x = 2) and bends (U3 = -0.1). Step 2 is `*TEMPERATURE, OP=NEW` without data lines. The plate should return to its initial state. Instead the stretch goes back to 0, but the bending stays at -0.1. Exit 0, no warning. ## Version ccx 2.23 (macOS arm64). Source: master 9ba5d76 (16 Oct 2026). ## Already reported or fixed? Not reported: I found no matching GitHub issue (open or closed) or pull request in Dhondtguido/CalculiX, and no calculix.discourse.group topic (searched 21 Oct 2026). Not fixed: `temperatures.f` is unchanged on master (9ba5d76). ## Minimal input `op_new.inp`: ```auto *NODE, NSET=NALL 1, 0, 0, 0. 2, 0.5, 0, 0. 3, 1, 0, 0. 4, 1.5, 0, 0. 5, 2, 0, 0. 6, 0, 0.5, 0. 7, 1, 0.5, 0. 8, 2, 0.5, 0. 9, 0, 1, 0. 10, 0.5, 1, 0. 11, 1, 1, 0. 12, 1.5, 1, 0. 13, 2, 1, 0. *ELEMENT, TYPE=S8R, ELSET=EALL 1, 1, 3, 11, 9, 2, 7, 10, 6 2, 3, 5, 13, 11, 4, 8, 12, 7 *MATERIAL, NAME=M *ELASTIC 1000., 0. *EXPANSION 1.E-3 *SHELL SECTION, ELSET=EALL, MATERIAL=M 0.1 *BOUNDARY 1, 1, 3 3, 2, 3 9, 3, 3 *INITIAL CONDITIONS, TYPE=TEMPERATURE NALL, 0. *STEP *STATIC *TEMPERATURE NALL, 20., 100. *NODE PRINT, NSET=NALL U *END STEP *STEP *STATIC *TEMPERATURE, OP=NEW *NODE PRINT, NSET=NALL U *END STEP ``` `op_new_explicit.inp`: step 2’s card also has the line `NALL, 0.`, i.e. the initial values written out. ## How to run ```auto ccx op_new ccx op_new_explicit ``` ## Expected In step 2 all temperatures and gradients are back at their initial values (0, no gradient), so the plate is back in its initial shape: U = 0. That is what `op_new_explicit.inp` gives. ## Actual Node 5 (x = 2, y = 0), exit 0, no warning: | deck | step 1 U1, U3 | step 2 U1, U3 | | --- | --- | --- | | op\_new | 4.000000E-02, -1.000000E-01 | 4.8E-16, -1.000000E-01 | | op\_new\_explicit | 4.000000E-02, -1.000000E-01 | 0, 0 | The mean temperature is reset; the gradient of step 1 is kept. With a data line for a single node (`1, 0.`), the gradient is reset for that node only: U3 = -1.041667E-01. ## Where it goes wrong temperatures.f lines 98-101: ```auto if((textpart(i).eq.'OP=NEW').and.(.not.temp_flag)) then do j=1,nk t1(j)=t0(j) enddo ``` t1 is reset to the initial temperatures t0. The gradients t1g are not reset to the initial gradients t0g (set by initialconditionss.f). gen3dtemp.f (lines 214-262) then builds the expanded nodes’ temperatures from the reset t1 and the old t1g. ## Fix Also reset the gradients for OP=NEW, where the gradient arrays exist: ```auto do j=1,nk t1(j)=t0(j) t1g(1,j)=t0g(1,j) t1g(2,j)=t0g(2,j) enddo ``` temperatures.f does not receive t0g today, so it would have to be passed in. Otherwise the manual should say that OP=NEW keeps the gradients. Workaround: repeat the initial temperatures (with their gradients) as data lines under `*TEMPERATURE, OP=NEW`. ---
**Author:** ![Calc\_em](https://avatars.discourse-cdn.com/v4/letter/c/43a26b/32.png) [@Calc\_em](https://calculix.discourse.group/u/Calc_em)\ **Post date:** [October 22, 2026, 9:06am UTC](https://calculix.discourse.group/t/temperature-op-new-resets-shell-and-beam-temperatures-to-the-initial-values-but-keeps-the-last-gradient-the-shell-stays-bent-exit-0/4213/2 "2026-10-22T09:06:27Z")
Confirmed using official build of ccx 2.23 on Windows, needs a GitHub ticket. op\_new.dat: step 1: `5 4.000000E-02 -4.404002E-15 -1.000000E-01` step 2: `5 1.288032E-16 2.593412E-16 -1.000000E-01` op\_new\_explicit.dat: step 1: `5 4.000000E-02 -4.404002E-15 -1.000000E-01` step 2: `5 0.000000E+00 0.000000E+00 0.000000E+00` ---
**Author:** ![Sandervdb](https://avatars.discourse-cdn.com/v4/letter/s/49beb7/32.png) [@Sandervdb](https://calculix.discourse.group/u/Sandervdb)\ **Post date:** [October 22, 2026, 6:02pm UTC](https://calculix.discourse.group/t/temperature-op-new-resets-shell-and-beam-temperatures-to-the-initial-values-but-keeps-the-last-gradient-the-shell-stays-bent-exit-0/4213/3 "2026-10-22T18:02:23Z")
Posted: [\*TEMPERATURE, OP=NEW resets shell and beam temperatures to the initial values but keeps the last gradient (the shell stays bent, exit 0) · Issue #262 · Dhondtguido/CalculiX · GitHub](https://github.com/Dhondtguido/CalculiX/issues/262)