Yuav ua li cas 10% txo nyob rau hauv Titanium Phab Ntsa Thickness Vim Uniform Corrosion hloov lub rhaub thawj hom kev vibration zaus thiab amplitude?

Lub ntuj vibration zaus nyob rau hauv thawj hom rau tus txheej txheem engineer soj ntsuam ib tug laus titanium immersion rhaub, uas tau raug tej yam niaj hnub phab ntsa thinning ntawm 10% (piv txwv li los ntawm 1.5 hli mus rau 1.35 hli) vim corrosion, txo li ntawm 5-10% thiab lub vibration amplitude nyob rau hauv tib 15% excitation quab yuam nce. Lub ntuj zaus f_n yog proportional rau sqrt (I / m), qhov twg kuv yog thaj tsam lub sij hawm ntawm inertia (∝ t³ rau nyias phab ntsa) thiab m yog loj ib chav tsev ntev (∝ t). 10% txo qis hauv t txo kuv li ntawm 27% (los ntawm 0.93 txog 0.73) thiab m los ntawm 10%. Tag nrho cov txiaj ntsig ntawm f_n yog sqrt(0.73/0.90)=sqrt(0.81){19}} Yog li f_n poob 10%. Lub amplitude ntawm lub vibration A nyob rau hauv resonant mob yog inversely proportional rau lub damping piv ζ uas yog tsis heev cuam tshuam los ntawm uniform phab ntsa thinning. Txawm li cas los xij, rau qhov tsis txaus ntseeg, nrog lub zog tsis tu ncua, qhov amplitude nce li ntawm 1/(f_n²), uas yog 23% amplitude nce (1/0.90²=1/0.81=1.23). Qhov amplitude ntau dua no ua rau qaug zog thiab fretting hnav ntawm cov ntsiab lus txhawb nqa.

Kev cuam tshuam ntawm phab ntsa thickness ntawm cov yam ntxwv vibrational
Thawj hom ntuj zaus ntawm cantilevered titanium rhaub raj yog muab los ntawm f_n=(λ² / 2πL²) × sqrt (EI / m) qhov twg λ=1.875 rau thawj hom dabtsi yog khoov, L yog ntev, E yog elastic modulus, I=π / 64 × (D⁴) yog thaj tsam ntawm lub sij hawm ntawm m (D⁴) huab hwm coj rau ib chav tsev ntev. Rau nyias-walled tube (t<< D) I~D^3*t and m~D*t. Uniform reduction in t reduces both I and m proportionate to t 1 and t 1 correspondingly but I has a further t 2 dependence from the (D 4 - d 4 ) expansion. A 10% drop of t to 1.35 mm for a 25 mm OD tube with 1.5 mm wall reduces I by 27% and m by 10%, and f_n by 10%. The amplitude of vibration $A$ for a harmonic force $F$ at a frequency $\omega$ is $A$ = $F$ / ($m$ * $\sqrt{(\omega_{n}^2 - \omega^2)^2 + (2\zeta\omega_{n}\omega)^2}$). The reaction increases because the near to resonance increases as f_n lowers.

Quantification ntawm cov kev hloov hauv vibration yam ntxwv nrog 10% Phab ntsa Thinning
Phab ntsa t (mm) Thinned Phab ntsa t (mm) Txo (%)I txo (%) m Txo (%) f_n Txo (%) Amplitude nce ntawm qhov Excit. (%)
1.5 1.35 10 27 10 9.5 22 2.0 1.80 10 26 10 9.0 21 2.5 2.25 10 25 10 8.5 20 1.0 0.90 10 28 10 10.0 23 1.5 (seamless) 1.35 10 27 10 9.5 22 1.5 (welded) 1.35 10 27 10 9.5 (tab sis damping qis) 28 (qis damping)
Kev taw qhia rau kev ntsuas kev vibration ntawm Thinned Heaters: Scenario Based
Rhaub Installation thiab kev khiav hauj lwm tej yam kev mobOriginal Phab ntsa (mm) Thinned phab ntsa (mm) f_n ua haujlwm (Hz) Resonance RiskSuggested Action
Ntsug, L=800 mm, low flow velocity (0.3 m/s) 1.5 1.35 18 → 16.3 Low (vortex shedding zaus deb tshaj f_n) Tsis tas yuav tsum ua
Kab rov tav, L=1,000 mm, hla- ntws 0.8 m/sec 1.5 1.35 5.2 → 4.7 Nruab nrab (0.8 × f_n ua ntej, tam sim no 0.9 × f_n vortex shedding) Tshawb nrhiav kev pab. Yog ua tau kom txo qhov ntws.
Kab rov tav, L=1,000 mm, hla ntws 0.9 m / s 1.5 1.35 5.2 → 4.7 Siab (vortex shedding tam sim no kuj coincide nrog f_n) Hloov lub rhaub lossis nruab ntau qhov kev txhawb nqa.
Txhua lub tshuab rhaub nrog lub xeev resonant ua ntej thinning 1.5 1.35 Ib qho siab heev (f_n hloov yuav txav mus rau resonance) Yuav tsum tau ntxiv kev pab tam sim .
Lub tshuab cua sov w / ntau qhov kev txhawb nqa (short spans) 1.5 1.35 > 30 → > 27 Tsawg (fn siab dhau rau vortex shedding) Tsis xav tau kev hloov pauv.
Lub rhaub dej kub hauv cov kua dej viscosity siab (damping siab) 1.5 1.35 18 → 16.3 Tsawg (cov kua dej viscosity suppresses vibration) Tsis tas yuav muaj kev cuam tshuam.
Kev ntsuam xyuas lub neej kev xav txog Engineering
Ultrasonic thickness kuaj kom pom cov phab ntsa nyias nyias ntawm 10% yuav tsum yog ib feem ntawm qhov seem ntawm lub neej ntsuas los ntsuas qhov kev hloov ntawm cov yam ntxwv ntawm kev co. Qhov kev txo qis hauv f_n (feem ntau yog 5 mus rau 10 feem pua) coj lub rhaub kom ze rau txhua qhov resonant zaus hauv lub kaw lus xws li vortex los ntawm kev hla ntws, impeller hniav hla zaus lossis khiav tawm ntawm lub zog. Yog tias tus qauv tsim muaj 20% kev nyab xeeb ntawm f_n thiab qhov ze tshaj plaws excitation zaus, ces 10% poob hauv f_n txo qhov kev nyab xeeb rau 10% -- tseem txaus. Yog hais tias tus thawj margin tsuas yog 10% thinning lub rhaub tam sim no yuav muab tso rau ntawm resonance. Lub fretting hnav ntawm cov ntsiab lus txhawb nqa yog nrawm los ntawm kev vibration amplitude siab dua (15-25%). PTFE lossis roj hmab txhawb nqa cov ntaub ntawv uas ib zaug tsim nyog tuaj yeem hnav los ntawm tam sim no, tso cai rau cov hlau-rau-hlau sib cuag thiab galvanic corrosion. Rau cov cua sov nrog 10% thinning ua hauj lwm ze rau resonant tej yam kev mob, qhov pib vibration margins tuaj yeem rov qab los ntawm kev txo qis qhov ntws tawm los ntawm 10-15% lossis los ntawm kev txhim kho kev txhawb nqa nruab nrab.

Kev xaus: 10% Phab ntsa Thinning Txo f_n los ntawm ~ 10% thiab nce Amplitude los ntawm ~ 20%
Uniform corrosion ntawm titanium rhaub phab ntsa thickness los ntawm 10% ua rau ib tug poob ntawm thawj hom ntuj vibration zaus li ntawm 9-10% thiab nce nyob rau hauv vibration amplitude nyob rau hauv tas li excitation los ntawm 20-25%. Qhov kev txo qis hauv zaus yog vim li ntawm 25-28% txo qis hauv cheeb tsam lub sijhawm ntawm inertia Kuv feem ntau cuam tshuam los ntawm 10% txo qis hauv huab hwm coj ib chav tsev ntev. Qhov nce hauv amplitude yog vim qhov sib txawv ntawm qhov sib txuas ntawm qhov amplitude thiab zaus ntawm resonance. Rau cov cua sov nyob ze rau cov xwm txheej resonance (vortex shedding, impeller frequencies) 10% thinning yuav ua rau lub rhaub kom resonate, ua rau ua rau qaug zog ntxov ntxov. Yog tias qhov kev soj ntsuam tuab qhia tias 10% tsis zoo ntawm phab ntsa, kev kawm vibration yuav tsum tau ua los txiav txim siab seb qhov kev hloov pauv zaus tau txo qis qhov kev nyab xeeb rau qib tsis txaus ntseeg. Nws raug nquahu kom txhim kho cov kev txhawb nqa nruab nrab, txo qis kev tshaj tawm lossis hloov lub tshuab cua sov hauv cov ntaub ntawv ntawm resonance.