A method of predicting growth of a crack in a member includes memorizing, for each portion on the member, stress distribution Δσ(a) in the depth direction obtained in the case that no crack is present, a relationship between depth of growing cracks and creep contribution, and a relationship between creep contribution and parameters C and in of the Paris's law, receiving from a user an indication of a certain portion on the member, acquiring the stress distribution Δσ(a) in the depth direction for the certain portion, acquiring a creep contribution at the depth of a growing crack for the certain portion, from the relationship between depth of cracks and creep contribution memorized for the certain portion, and acquiring parameters C and in corresponding to the acquired creep contribution, from the relationship between creep contribution and parameters C and m of the Paris's law memorized for the certain portion.
Please help me write a proper abstract based on the patent claims. CLAIM: 1. A method of predicting growth of a crack in a member comprising the steps, executed by an information processing device, of: memorizing, for each portion on the member, stress distribution Δσ(a) in the depth direction obtained in the case that no crack is present, a relationship between depth of growing cracks and creep contribution, and a relationship between creep contribution and parameters C and m of the Paris's law; receiving from a user an indication of a certain portion on the member; acquiring the stress distribution Δσ(a) in the depth direction for the certain portion; acquiring a creep contribution at the depth of a growing crack for the certain portion, from the relationship between depth of cracks and creep contribution memorized for the certain portion; acquiring parameters C and m corresponding to the acquired creep contribution, from the relationship between creep contribution and parameters C and m of the Paris's law memorized for the certain portion; and predicting the growth of the crack in the certain portion, based on the following equations: da/dN=C×(ΔK)m, and ΔK=Δσ(a)×(π×a)1/2 wherein “a” is a crack depth, N is a number of occurrences of a cyclic stress, C and m are constants determined for a member, and ΔK is a stress intensity factor range. 2. The method according to claim 1, wherein the relationship between depth of cracks and creep contribution memorized by the information processing device is calculated based on temporal change of stress at a depth of a growing crack in the member, a creep rupture property, a measured value of a number of occurrences of a cyclic stress before a crack occurs in a portion on the member. 3. The method according to claim 2, comprising the steps, executed by an information processing device, of: acquiring, from the user, a length of the crack appeared on a surface of the certain portion; predicting a depth of the crack occurred in the certain portion based on the length of the crack; and defining the predicted depth of the crack as an initial value to be used in predicting a growth of a crack in the certain portion. 4. The method according to claim 3, wherein by the information processing device a value obtained by multiplying the acquired length of the crack appeared on the surface of the certain portion with ⅓ is used as a predicted value for the depth of the crack occurred in the certain portion. 5. The method according to claim 1, wherein by the information processing device, when a curve representing the relationship between number N of the cyclic stresses and length “a” of a crack, the curve being obtained by predicting growth of cracks in the certain portion, has a steeply changing segment where the length “a” of the crack steeply changes relative to the change in the number N of the cyclic stresses, the curve is corrected by drawing a tangent line on an upwardly convex portion of the steeply changing segment from the vicinity of the origin. 6. The method according to claim 1, wherein the stress distribution Δσ(a) in the depth direction obtained in the case that no crack is present for each portion on the member is obtained by: choosing, among known stress-strain properties, a property that satisfies the following equations: 1/Nf=1/Npp+1/Ncp, Δεcp=A2×Ncp−α2, and Δεpp=A1×Npp−α1 wherein Nf is a known number of occurrences of cracks in the portion, Ncp is a number of occurrences of cracks of a cp type (tensile creep strain+compressive plasticity strain) in strain range partitioning, Npp is a number of occurrences of cracks of a pp type (tensile plasticity strain+compressive plasticity strain) in the strain range partitioning, Δεcp is a cp strain range in the strain range partitioning, Δεpp is a pp strain range in the strain range partitioning, and A1, A2, α1, and α2 are all experimentally calculated constants; and determining stress distribution Δσ(0) of the portion in the case that no crack is present in the portion based on the chosen stress-strain property to perform a numerical analysis based on the Δσ(0), and wherein: by the information processing device the growth of the crack in the portion is predicted according to the acquired stress distribution Δσ(a) and the following equations: da/dN=C×(ΔK)m, and ΔK=Δσ(a)×(π×a)1/2 wherein “a” is a crack depth, N is a number of occurrences of a cyclic stress, C and m are constants determined for a member, and ΔK is a stress intensity factor range. 7. An information processing device comprising: a central processing unit (CPU); a memory; means for memorizing, for each portion on a member, stress distribution Δσ(a) in the depth direction obtained in the case no crack is present, a relationship between depth of growing cracks and creep contribution, and a relationship between creep contribution and parameters C and m of the Paris's law; means for receiving from a user an indication of a certain portion on the member; means for acquiring the stress distribution Δσ(a) in the depth direction for the certain portion; means for acquiring a creep contribution at the depth of a growing crack for the certain portion, from the relationship between depth of cracks and creep contribution memorized for the certain portion; means for acquiring parameters C and m corresponding to the acquired creep contribution, from the relationship between creep contribution and parameters C and m of the Paris's law memorized for the certain portion; and means for predicting the growth of the crack in the certain portion, based on the following equations: da/dN=C×(ΔK)m, and ΔK=Δσ(a)×(π×a)1/2 wherein “a” is a crack depth, N is a number of occurrences of a cyclic stress, C and m are constants determined for a member, and ΔK is a stress intensity factor range. 8. The information processing device according to claim 7, wherein the relationship between depth of cracks and creep contribution is calculated based on temporal change of stress at a depth of a growing crack in the member, a creep rupture property, a measured value of a number of occurrences of a cyclic stress before a crack occurs in a portion. 9. The information processing device according to claim 8, further comprising: means for acquiring, from the user, a length of the crack appeared on a surface of the certain portion; means for predicting a depth of the crack occurred in the certain portion based on the length of the crack; and means for defining the predicted depth of the crack as an initial value to be used in predicting a growth of a crack in the certain portion. 10. The information processing device according to claim 9, wherein a value obtained by multiplying the acquired length of the crack appeared on the surface of the certain portion with ⅓ is used as a predicted value for the depth of the crack occurred in the certain portion. 11. The information processing device according to claim 7, further comprising: means for correcting a curve representing the relationship between number N of the cyclic stresses and a length “a” of a crack, the curve being obtained by predicting growth of cracks in the certain portion, when the curve has a steeply changing segment where the length “a” of the crack steeply changes relative to the change in the number N of the cyclic stresses, the curve is corrected by drawing a tangent line on an upwardly convex portion of the steeply changing segment from the vicinity of the origin. 12. The information processing device according to claim 7, further comprising: means for obtaining the stress distribution Δσ(a) in the depth direction obtained in the case no crack is present for each portion on the member by: choosing, among known stress-strain properties, a property that satisfies the following equations: 1/Nf=1/Npp+1/Ncp, Δεcp=A2×Ncp−α2, and Δεpp=A1×Npp−α1 wherein Nf is a known number of occurrences of cracks in the portion, Ncp is a number of occurrences of cracks of a cp type (tensile creep strain+compressive plasticity strain) in strain range partitioning, Npp is a number of occurrences of cracks of a pp type (tensile plasticity strain+compressive plasticity strain) in the strain range partitioning, Δεcp is a cp strain range in the strain range partitioning, Δεpp is a pp strain range in the strain range partitioning, and A1, A2, α1, and α2 are all experimentally calculated constants; and determining stress distribution Δσ(0) of the portion in the case no crack is present in the portion based on the chosen stress-strain property to perform a numerical analysis based on the Δσ(0); and means for predicting the growth of the crack in the portion according to the acquired stress distribution Δσ(a) and the following equations (Paris's law): da/dN=C×(ΔK)m, and ΔK=Δσ(a)×(π×a)1/2 wherein “a” is a crack depth, N is a number of occurrences of a cyclic stress, C and m are constants determined for a member, and ΔK is a stress intensity factor range. 13. The method according to claim 1, comprising the steps, executed by an information processing device, of: acquiring, from the user, a length of the crack appeared on a surface of the certain portion; predicting a depth of the crack occurred in the certain portion based on the length of the crack; and defining the predicted depth of the crack as an initial value to be used in predicting a growth of a crack in the certain portion. 14. The method according to claim 13, wherein by the information processing device a value obtained by multiplying the acquired length of the crack appeared on the surface of the certain portion with ⅓ is used as a predicted value for the depth of the crack occurred in the certain portion. 15. The method according to claim 13, wherein by the information processing device, when a curve representing the relationship between number N of the cyclic stresses and length “a” of a crack, the curve being obtained by predicting growth of cracks in the certain portion, has a steeply changing segment where the length “a” of the crack steeply changes relative to the change in the number N of the cyclic stresses, the curve is corrected by drawing a tangent line on an upwardly convex portion of the steeply changing segment from the vicinity of the origin. 16. The method according to claim 5, wherein the stress distribution Δσ(a) in the depth direction obtained in the case that no crack is present for each portion on the member is obtained by: choosing, among known stress-strain properties, a property that satisfies the following equations: 1/Nf=1/Npp+1/Ncp, Δεp=A2×Ncp−α2, and Δεpp=A1×Npp−α1 wherein Nf is a known number of occurrences of cracks in the portion, Ncp is a number of occurrences of cracks of a cp type (tensile creep strain+compressive plasticity strain) in strain range partitioning, Npp is a number of occurrences of cracks of a pp type (tensile plasticity strain+compressive plasticity strain) in the strain range partitioning, Δεcp is a cp strain range in the strain range partitioning, Δεpp is a pp strain range in the strain range partitioning, and A1, A2, α1, and α2 are all experimentally calculated constants; and determining stress distribution Δσ(0) of the portion in the case that no crack is present in the portion based on the chosen stress-strain property to perform a numerical analysis based on the Δσ(0), and wherein: by the information processing device the growth of the crack in the portion is predicted according to the acquired stress distribution Δσ(a) and the following equations: da/dN=C×(ΔK)m, and ΔK=Δσ(a)×(π×a)1/2 wherein “a” is a crack depth, N is a number of occurrences of a cyclic stress, C and m are constants determined for a member, and ΔK is a stress intensity factor range. 17. The method according to claim 13, wherein the stress distribution Δσ(a) in the depth direction obtained in the case that no crack is present for each portion on the member is obtained by: choosing, among known stress-strain properties, a property that satisfies the following equations: 1/Nf=1/Npp+1/Ncp, Δεcp=A2×Ncp−α2, and Δεpp=A1×Npp−α1 wherein Nf is a known number of occurrences of cracks in the portion, Ncp is a number of occurrences of cracks of a cp type (tensile creep strain+compressive plasticity strain) in strain range partitioning, Npp is a number of occurrences of cracks of a pp type (tensile plasticity strain+compressive plasticity strain) in the strain range partitioning, Δεcp is a cp strain range in the strain range partitioning, Δεpp is a pp strain range in the strain range partitioning, and A1, A2, α1, and α2 are all experimentally calculated constants; and determining stress distribution Δσ(0) of the portion in the case that no crack is present in the portion based on the chosen stress-strain property to perform a numerical analysis based on the Δσ(0), and wherein: by the information processing device the growth of the crack in the portion is predicted according to the acquired stress distribution Δσ(a) and the following equations: da/dN=C×(ΔK)m, and ΔK=Δσ(a)×(π×a)1/2 wherein “a” is a crack depth, N is a number of occurrences of a cyclic stress, C and m are constants determined for a member, and ΔK is a stress intensity factor range. 18. The method according to claim 14, wherein the stress distribution Δσ(a) in the depth direction obtained in the case that no crack is present for each portion on the member is obtained by: choosing, among known stress-strain properties, a property that satisfies the following equations: 1/Nf=1/Npp+1/Ncp, Δεcp=A2×Ncp−α2, and Δεpp=A1×Npp−α1 wherein Nf is a known number of occurrences of cracks in the portion, Ncp is a number of occurrences of cracks of a cp type (tensile creep strain+compressive plasticity strain) in strain range partitioning, Npp is a number of occurrences of cracks of a pp type (tensile plasticity strain+compressive plasticity strain) in the strain range partitioning, Δεcp is a cp strain range in the strain range partitioning, Δεpp is a pp strain range in the strain range partitioning, and A1, A2, α1, and α2 are all experimentally calculated constants; and determining stress distribution Δσ(0) of the portion in the case that no crack is present in the portion based on the chosen stress-strain property to perform a numerical analysis based on the Δσ(0), and wherein: by the information processing device the growth of the crack in the portion is predicted according to the acquired stress distribution Δσ(a) and the following equations: da/dN=C×(ΔK)m, and ΔK=Δσ(a)×(π×a)1/2 wherein “a” is a crack depth, N is a number of occurrences of a cyclic stress, C and in are constants determined for a member, and ΔK is a stress intensity factor range. 19. The method according to claim 15, wherein the stress distribution Δσ(a) in the depth direction obtained in the case that no crack is present for each portion on the member is obtained by: choosing, among known stress-strain properties, a property that satisfies the following equations: 1/Nf=1/Npp+1/Ncp, Δεcp=A2×Ncp−α2, and Δεpp=A1×Npp−α1 wherein Nf is a known number of occurrences of cracks in the portion, Ncp is a number of occurrences of cracks of a cp type (tensile creep strain+compressive plasticity strain) in strain range partitioning, Npp is a number of occurrences of cracks of a pp type (tensile plasticity strain+compressive plasticity strain) in the strain range partitioning, Δεcp is a cp strain range in the strain range partitioning, Δεpp is a pp strain range in the strain range partitioning, and A1, A2, α1, and α2 are all experimentally calculated constants; and determining stress distribution Δσ(0) of the portion in the case that no crack is present in the portion based on the chosen stress-strain property to perform a numerical analysis based on the Δσ(0), and wherein: by the information processing device the growth of the crack in the portion is predicted according to the acquired stress distribution Δσ(a) and the following equations: da/dN=C×(ΔK)m, and ΔK=Δσ(a)×(π×a)1/2 wherein “a” is a crack depth, N is a number of occurrences of a cyclic stress, C and m are constants determined for a member, and ΔK is a stress intensity factor range. 20. The information processing device according to claim 7, comprising: means for acquiring, from the user, a length of the crack appeared on a surface of the certain portion; means for predicting a depth of the crack occurred in the certain portion based on the length of the crack; and means for defining the predicted depth of the crack as an initial value to be used in predicting a growth of a crack in the certain portion. 21. The information processing device according to claim 20, wherein a value obtained by multiplying the acquired length of the crack appeared on the surface of the certain portion with ⅓ is used as a predicted value for the depth of the crack occurred in the certain portion. 22. The information processing device according to claim 20, comprising: means for correcting a curve representing the relationship between number N of the cyclic stresses and a length “a” of a crack, the curve being obtained by predicting growth of cracks in the certain portion, when the curve has a steeply changing segment where the length “a” of the crack steeply changes relative to the change in the number N of the cyclic stresses, the curve is corrected by drawing a tangent line on an upwardly convex portion of the steeply changing segment from the vicinity of the origin. 23. The information processing device according to claim 11, comprising: means for obtaining the stress distribution Δσ(a) in the depth direction obtained in the case no crack is present for each portion on the member by: choosing, among known stress-strain properties, a property that satisfies the following equations: 1/Nf=1/Npp+1/Ncp, ΔΣcp=A2×Ncp−α2, and Δεpp=A1×Npp−α1 wherein Nf is a known number of occurrences of cracks in the portion, Ncp is a number of occurrences of cracks of a cp type (tensile creep strain+compressive plasticity strain) in strain range partitioning, Npp is a number of occurrences of cracks of a pp type (tensile plasticity strain+compressive plasticity strain) in the strain range partitioning, Δεcp is a cp strain range in the strain range partitioning, Δεpp is a pp strain range in the strain range partitioning, and A1, A2, α1, and α2 are all experimentally calculated constants; and determining stress distribution Δσ(0) of the portion in the case no crack is present in the portion based on the chosen stress-strain property to perform a numerical analysis based on the Δσ(0); and means for predicting the growth of the crack in the portion according to the acquired stress distribution Δσ(a) and the following equations (Paris's law): da/dN=C×(ΔK)m, and ΔK=Δσ(a)×(π×a)1/2 wherein “a” is a crack depth, N is a number of occurrences of a cyclic stress, C and m are constants determined for a member, and ΔK is a stress intensity factor range. 24. The information processing device according to claim 20, comprising: means for obtaining the stress distribution Δσ(a) in the depth direction obtained in the case no crack is present for each portion on the member by: choosing, among known stress-strain properties, a property that satisfies the following equations: 1/Nf=1/Npp+1/Ncp, Δεcp=A2×Ncp−α2, and Δεpp=A1×Npp−α1 wherein Nf is a known number of occurrences of cracks in the portion, Ncp is a number of occurrences of cracks of a cp type (tensile creep strain+compressive plasticity strain) in strain range partitioning, Npp is a number of occurrences of cracks of a pp type (tensile plasticity strain+compressive plasticity strain) in the strain range partitioning, Δεcp is a cp strain range in the strain range partitioning, Δεpp is a pp strain range in the strain range partitioning, and A1, A2, α1, and α2 are all experimentally calculated constants; and determining stress distribution Δσ(0) of the portion in the case no crack is present in the portion based on the chosen stress-strain property to perform a numerical analysis based on the Δσ(0); and means for predicting the growth of the crack in the portion according to the acquired stress distribution Δσ(a) and the following equations (Paris's law): da/dN=C×(ΔK)m, and ΔK=Δσ(a)×(π×a)1/2 wherein “a” is a crack depth, N is a number of occurrences of a cyclic stress, C and m are constants determined for a member, and ΔK is a stress intensity factor range. 25. The information processing device according to claim 20, comprising: means for obtaining the stress distribution Δσ(a) in the depth direction obtained in the case no crack is present for each portion on the member by: choosing, among known stress-strain properties, a property that satisfies the following equations: 1/Nf=1/Npp+1/Ncp, Δεcp=A2×Ncp−α2, and Δεpp=A1×Npp−α1 wherein Nf is a known number of occurrences of cracks in the portion, Ncp is a number of occurrences of cracks of a cp type (tensile creep strain+compressive plasticity strain) in strain range partitioning, Npp is a number of occurrences of cracks of a pp type (tensile plasticity strain+compressive plasticity strain) in the strain range partitioning, Δεcp is a cp strain range in the strain range partitioning, Δεpp is a pp strain range in the strain range partitioning, and A1, A2, α1, and α2 are all experimentally calculated constants; and determining stress distribution Δσ(0) of the portion in the case no crack is present in the portion based on the chosen stress-strain property to perform a numerical analysis based on the Δσ(0); and means for predicting the growth of the crack in the portion according to the acquired stress distribution Δσ(a) and the following equations (Paris's law): da/dN=C×(ΔK)m, and ΔK=Δσ(a)×(π×a)1/2 wherein “a” is a crack depth, N is a number of occurrences of a cyclic stress, C and in are constants determined for a member, and ΔK is a stress intensity factor range. 26. The information processing device according to claim 20, comprising: means for obtaining the stress distribution Δσ(a) in the depth direction obtained in the case no crack is present for each portion on the member by: choosing, among known stress-strain properties, a property that satisfies the following equations: 1/Nf=1/Npp+1/Ncp, Δεcp=A2×Ncp−α2, and Δεpp=A1×Npp+α1 wherein Nf is a known number of occurrences of cracks in the portion, Ncp is a number of occurrences of cracks of a cp type (tensile creep strain+compressive plasticity strain) in strain range partitioning, Npp is a number of occurrences of cracks of a pp type (tensile plasticity strain+compressive plasticity strain) in the strain range partitioning, Δεp is a cp strain range in the strain range partitioning, Δεpp is a pp strain range in the strain range partitioning, and A1, A2, α1, and α2 are all experimentally calculated constants; and determining stress distribution Δσ(0) of the portion in the case no crack is present in the portion based on the chosen stress-strain property to perform a numerical analysis based on the Δσ(0); and means for predicting the growth of the crack in the portion according to the acquired stress distribution Δσ(a) and the following equations (Paris's law): da/dN=C=(ΔK)m, and ΔK=Δσ(a)=(π×a)1/2 wherein “a” is a crack depth, N is a number of occurrences of a cyclic stress, C and in are constants determined for a member, and ΔK is a stress intensity factor range.