RitaMath

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system_of_PDE.mw

NULL

NULL

Digits := 30; with(PDEtools); with(plots); Ops1 := numpoints = 100; Ops2 := color = magenta; Ops3 := color = blue; Ops4 := color = "BlueViolet"; Ops5 := axes = boxed, shading = zhue, orientation = [40, 50]; a := 0; b := 1; Tf := .5

axes = boxed, shading = zhue, orientation = [40, 50]

 

.5

(1)

E := 1480

1480

(2)

Ebes := 5990

5990

(3)

n0 := 900000

900000

(4)

ro := 1200

1200

(5)

m := 12.6

12.6

(6)

f := sig(x, t)-Ebes*`ϵij`(x, t)

sig(x, t)-5990*`ϵij`(x, t)

(7)

n := 900000*exp(-(sig(x, t)-E*`ϵij`(x, t))/m)

900000*exp(-0.793650793650793650793650793651e-1*sig(x, t)+117.460317460317460317460317460*`ϵij`(x, t))

(8)

NULL

P := 5

5

(9)

w := 4

4

(10)

k := 7

7

(11)

i := 5

5

(12)

eq1 := diff(sig(x, t), x, x) = ro*(diff(sig(x, t), x, x))/E+ro*(diff(sig(x, t), t)-Ebes*f/(9000000*exp(-(sig(x, t)-E*`ϵij`(x, t))/m)))*(1+f/m)/(9000000*exp(-(sig(x, t)-E*`ϵij`(x, t))/m))

diff(diff(sig(x, t), x), x) = (30/37)*(diff(diff(sig(x, t), x), x))+(1/7500)*(diff(sig(x, t), t)-(599/900000)*(sig(x, t)-5990*`ϵij`(x, t))/exp(-0.793650793650793650793650793651e-1*sig(x, t)+117.460317460317460317460317460*`ϵij`(x, t)))*(1+0.793650793650793650793650793651e-1*sig(x, t)-475.396825396825396825396825397*`ϵij`(x, t))/exp(-0.793650793650793650793650793651e-1*sig(x, t)+117.460317460317460317460317460*`ϵij`(x, t))

(13)

 

eq2 := diff(`ϵij`(x, t), t) = f/(9000000*exp(-(sig(x, t)-E*`ϵij`(x, t))/m))

diff(`ϵij`(x, t), t) = (1/9000000)*(sig(x, t)-5990*`ϵij`(x, t))/exp(-0.793650793650793650793650793651e-1*sig(x, t)+117.460317460317460317460317460*`ϵij`(x, t))

(14)

NULL

sys := {eq1, eq2}

{diff(diff(sig(x, t), x), x) = (30/37)*(diff(diff(sig(x, t), x), x))+(1/7500)*(diff(sig(x, t), t)-(599/900000)*(sig(x, t)-5990*`ϵij`(x, t))/exp(-0.793650793650793650793650793651e-1*sig(x, t)+117.460317460317460317460317460*`ϵij`(x, t)))*(1+0.793650793650793650793650793651e-1*sig(x, t)-475.396825396825396825396825397*`ϵij`(x, t))/exp(-0.793650793650793650793650793651e-1*sig(x, t)+117.460317460317460317460317460*`ϵij`(x, t)), diff(`ϵij`(x, t), t) = (1/9000000)*(sig(x, t)-5990*`ϵij`(x, t))/exp(-0.793650793650793650793650793651e-1*sig(x, t)+117.460317460317460317460317460*`ϵij`(x, t))}

(15)

NULL

IBC1 := {sig(0, t) = P*sin(w*k*i), sig(10, t) = P*sin(w*k*i), sig(x, 0) = 0, sig(x, 1) = 0, `ϵij`(x, 0) = 0}

{sig(0, t) = 5*sin(140), sig(10, t) = 5*sin(140), sig(x, 0) = 0, sig(x, 1) = 0, `ϵij`(x, 0) = 0}

(16)

S := 1/100; Ops := spacestep = S, timestep = S; Sol1 := pdsolve(sys, IBC1, [sig, `ϵij`], numeric, time = t, range = a .. b, Ops)

1/100

 

spacestep = 1/100, timestep = 1/100

 

Error, (in pdsolve/numeric) unable to handle elliptic PDEs

 

``

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