JP2016057211A - Welding deformation analysis device, method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a welding deformation analysis technology implemented highly accurately without increasing the information amount of a database based on an inherent strain method.SOLUTION: The welding deformation analysis device 10 includes a first calculation part 11 (11a) for calculating (n-1)-th inherent strain distributed on the welding part of a joint model by n-1 times of welding operations, a second calculation part 11 (11b) for calculating n-th inherent strain distributed on the welding part of the joint model welded by n times of welding operations, a difference strain deriving part 12 for deriving difference strain distributed to the welding part of the joint model singly by the n times of welding operations based on a difference between the n-th inherent strain and the (n-1)-th inherent strain, a registration part 13 for registering first inherent strain and each difference strain up to the n-th, an analysis execution part 14 for applying the first inherent strain or the difference strain corresponding to each welding path to a structure model to execute deformation analysis, and a result reflection part 15 for reflecting each result of the execution and the deformation analysis of the welding path 61 in the structure model according to the order of execution.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a technique for analyzing deformation that occurs during welding of a structure.

Thermal elasto-plastic analysis methods using the finite element method and intrinsic strain methods are widely adopted as methods for analyzing deformations occurring during welding of structures by computer simulation.
Among these, the thermoelastic-plastic analysis method is a method for performing detailed analysis based on the physical properties of the welded member and the temperature characteristics of the physical property, and is not practical for analyzing the welding deformation of a large or complex structure.

  On the other hand, the eigenstrain method is a technique that uses an elastic analysis method that can perform linear analysis. Therefore, the calculation time can be shortened, and even in a large-scale analysis, the calculation load is small and welding of a large or complex structure is required. It can deal with deformation analysis.

  In the inherent strain method, the inherent strain generated in the welded portion of a simple-scale joint model is obtained by detailed analysis such as thermoelastic-plastic analysis and is made into a database. Then, it is a technique for analyzing the welding deformation of the entire structure by applying an elastic analysis to the welded part of a large-scale or complex actual structure to be analyzed by applying the inherent strain acquired from this database (for example, Patent Documents 1, 2).

JP-A-6-180271 Japanese Patent Laid-Open No. 2006-879

Based on the above-described principle, the analysis accuracy of welding deformation by the inherent strain method depends on the fidelity of the inherent strain obtained from the joint model to the inherent strain generated in the weld of the actual structure.
On the other hand, since the welding phenomenon is closely related to the movement phenomenon of the welding heat source, it is known that the welding deformation of the structure having a plurality of welds largely depends on the welding pass construction sequence.

However, in the conventional inherent strain method, it is difficult to perform an analysis in consideration of the welding pass execution sequence.
This is because, if the influence of the welding sequence is strictly considered, it is necessary to perform detailed analysis of the inherent strain of the joint model in which the constraint conditions and the like are changed in various ways, and to dramatically improve the database from the current state.

  Furthermore, when considering the case where multilayer welding is applied to each of the plurality of welds, the amount of information on the inherent strain of the joint model registered in the database becomes enormous with the increase in the combination of the welding pass order. End up.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a welding deformation analysis technique that can be carried out with high accuracy based on the inherent strain method without increasing the amount of information in a database. To do.

  In the welding deformation analysis apparatus, welding is performed by n-1 times (where n is a natural number equal to or greater than 2) a first calculation unit that calculates the (n-1) inherent strain distributed in the welded portion and n times of welding operations. A second computing unit that computes the nth inherent strain distributed in the welded portion of the joint model, and the nth welding operation based solely on the difference between the nth inherent strain and the n-1th intrinsic strain. A differential strain deriving unit for deriving the differential strain distributed in the part, a registration unit for registering each of the differential strains up to the first intrinsic strain and the n-th in the joint model, and a structure to be subjected to deformation analysis A structure model construction section for constructing a model, a plurality of welding paths to be constructed on the structure model and a welding path setting section for setting the order thereof, and the first intrinsic strain corresponding to each of the welding paths or the Difference An analysis execution unit that applies deformation to the structure model and executes the deformation analysis; and a result reflection unit that reflects the results of the welding path construction and the deformation analysis in the structure model according to the order of the construction each time; It is characterized by providing.

  The present invention provides a welding deformation analysis technique that can be carried out with high accuracy based on the inherent strain method without increasing the amount of information in the database.

The block diagram which shows the welding deformation | transformation analyzer which concerns on embodiment of this invention. (A) The perspective view which shows the joint model of T-shaped welding, (B) The perspective view which shows the joint model of butt welding. (A) Cross-sectional view of a T-welded joint model welded with a single layer by one welding operation, (B) Cross-sectional view of a T-welded joint model welded with a single layer by two welding operations, (C) 6 Sectional drawing of the joint model of T-shaped welding which carried out multilayer welding by the welding operation of 1 time. (A) The perspective view of the structure model used as the object of a deformation | transformation analysis, (B) The top view of this structure model. The flowchart of the welding deformation | transformation analysis method and program which concern on embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
The welding deformation analysis apparatus 10 according to the embodiment includes an (n-1) th inherent strain 51 distributed in the welded portion of the joint model (FIG. 3A) by n-1 times (n = 2, and the following description is continued). a first calculation unit 11 for calculating a ₁ (11a), n times welded joint model welding operation of the second operational unit 11 for computing the first n inherent strain 51 ₂ distributed in welds (Fig. 3B) (11b ) And the difference between the nth intrinsic strain 51 ₂ and the n−1 intrinsic strain 51 ₁ , the nth welding operation alone derives the differential strain distributed to the welded portion of the joint model (FIG. 3B). The differential strain deriving unit 12, the registration unit 13 for registering each of the first inherent strain 51 ₁ and the nth differential strain in the joint model, and a structure model (FIG. 4) to be subjected to deformation analysis are constructed. Structure model construction unit 24 and structure A plurality of welding paths 61 (61A to 61L) constructed in the model (FIG. 4) and a welding path setting unit 25 for setting the order thereof, and a first inherent strain 51 corresponding to each welding path 61 (61A to 61L). _The analysis execution unit 14 that applies deformation strain analysis by applying ₁ or differential strain to the structure model (FIG. 4), and the results of construction and deformation analysis of the welding pass 61 are applied to the structure model (FIG. 4) according to the order of construction. And a result reflecting unit 15 for reflecting each time.

The joint model selection unit 21 selects a joint model in which a welding mode and a welding path are defined.
As the shape and dimensions of the joint model, a shape simulating the groove shape and the plate thickness of the members constituting the structure model (FIG. 4) is adopted.
Specifically, the plate width is about 200 to 300 mm and the weld line direction width is about 300 mm, which are dimensions capable of structurally and thermally stably performing welding.

In the above description, as an example of the joint model, a single-layer welding pass 53 ₁ , 53 ₂ is formed twice on both sides of the contact portion of the member as shown in FIG. n = 2) The case where construction was performed was described as an example.
However, the joint model selected is not limited to this, and there are a butt welding mode as shown in FIG. 2B and other welding modes, as shown in FIG. 3C. Welding passes 53 _{1 to} 53 ₆ (n = 6 in the illustration in the figure) may be applied.
That is, the number n of welding operations can be generalized as a natural number of 2 or more.

  The welding condition input unit 22 inputs welding conditions necessary for calculation of the inherent strain in the inherent strain calculation unit 11. The welding conditions include, but are not limited to, the type of welding, current during welding, voltage, welding speed, torch angle, welding wire supply speed, heat input efficiency, and the like.

The material physical property input unit 23 inputs material physical properties of members constituting the structure model (FIG. 4). Thermal material properties include thermal conductivity and specific heat, and mechanical material properties include Young's modulus, yield strength, linear expansion coefficient, work hardening index, and the like.
Furthermore, the physical properties of these materials can be expressed in terms of temperature dependence from room temperature to the melting temperature of the metal and hysteresis accompanying phase transformation.

The welding operation causes thermal expansion / contraction caused by a local temperature rise, but an area where free deformation is hindered by a portion where the surrounding temperature does not rise occurs. Such a region produces residual stress mainly in the welded part and its periphery, accompanied by compressive plastic deformation.
Intrinsic strain is a concept introduced to explain local mechanical incompatibility that causes such residual stress.

The inherent strain calculation unit 11 is based on the welding condition and material property information input from the welding condition input unit 22 and the material property input unit 23 with respect to the joint model (FIG. 2) selected by the joint model selection unit 21. The intrinsic strain distributed in the welded part of the joint model is calculated.
In the intrinsic strain calculation unit 11, a thermoelastic-plastic analysis method for performing detailed analysis based on the material physical properties of the welded member and the material temperature characteristics of the physical properties is employed.
By this thermoelastic-plastic analysis method, the inherent strain generated in the vicinity of the weld is calculated based on the result of the heat conduction analysis by the welding heat source and the material physical properties.

When the number of welding operations for the joint model is n, the inherent strain calculation unit 11 follows the construction order, the first inherent strain 51 ₁ by the first welding pass 53 ₁ , the first and second welding passes 53. ₁ , 53 ₂ , second intrinsic strain 51 ₂ , first to third welding passes 53 ₁ , 53 ₂ , 53 ₃ , third intrinsic strain 51 ₃ ,..., First to nth welding passes 53 ₁ to 53 _n and outputs the operation result of n inherent strain as the n inherent strain 51 _n by.

The differential strain deriving unit 12 includes a second differential strain based on the difference between the second intrinsic strain 51 ₂ and the first intrinsic strain 51 _1, a third differential strain based on the difference between the third intrinsic strain 51 ₃ and the second intrinsic strain 51 _2. ,... The nth differential strain is derived based on the difference between the nth inherent strain 51 _n and the (n−1) th inherent strain 51 _n−1 .
In this way, the differential strain deriving unit 12 derives the differential strain that each welding operation from the second time to the n-th time is independently distributed to the welded portion of the joint model.

  Such differential strain derivation occurs on the surface where the inherent strain is generated structurally and thermally stably (for example, the center plane of the weld line) after the welding pass is applied to the element near the weld of the joint model. 6 inherent strains (normal strain 3 components and shear strain 3 components) are extracted.

  Next, the differential strain generated by each welding pass independently is separated from the extracted inherent strain. Note that the value of the inherent strain includes the influence of the residual strain of the existing welding pass in the generation of the inherent strain and the effect of remelting by the subsequent welding pass. For this reason, the differential strain caused by a single welding pass can be determined strictly.

The registration unit 13 registers the first inherent strain 51 ₁ and the differential strains up to the n-th time derived by the calculation unit 11 and the derivation unit 12 for the joint model.
The plurality of differential strains registered in this way are input to the analysis execution unit 14 as analysis initial values for executing the welding deformation analysis of the structure model (FIG. 4).

The structure model constructing unit 24 constructs a structure model (FIG. 4) to be subjected to deformation analysis by combining the constituent members 62 (62A to 62D).
The structure model in the initial state is configured in a state in which there is no welding path 61 and the respective constituent members 62 are not restrained from each other.
Then, the structure model construction unit 24 can reconstruct the structure model by sequentially reflecting the influence (restraint, thermal deformation) of the welding path 61 constructed according to the welding order.

  The welding path setting unit 25 recognizes a place where the structural members 62 (62A to 62D) of the structure model are in contact with each other as a welding part, and a plurality of welding paths 61 (61A to 61L) to be constructed in the welded part and its Set the order.

The analysis execution unit 14 acquires the first inherent strain 51 or the differential strain corresponding to each welding path 61 (61 </ b> A to 61 </ b> L) from the registration unit 13 in the order set by the welding path setting unit 25. Then the first natural strain 51 ₁ or differential strain obtained was applied to a portion of the corresponding weld pass 61, and executes the deformation analysis of the structure model (FIG. 4).
Note that the deformation analysis of the structure model (FIG. 4) in the analysis execution unit 14 is performed each time the welding paths 61 are sequentially added, and the result is output each time.

The analysis execution unit 14 performs linear elastic analysis based on the applied first inherent strain 51 ₁ or differential strain. Specifically, using a general-purpose finite element method code, an inherent strain (differential strain) is given as an internal force, and the deformation of the entire structure model at that time is obtained.
Thereby, deformation analysis of a large-scale or complex structure model (FIG. 4) can be easily performed.
Although not shown in the figure, when the welding path has a curved shape, it is possible to perform an analysis by applying the inherent strain along the curved shape by performing coordinate transformation of the inherent strain or the like.

The result reflecting unit 15 reflects the result of construction and deformation analysis of the welding path 61 in the structure model (FIG. 4) in accordance with the order of construction.
That is, as the welding path 61 (61A to 61L) is sequentially constructed, the constraint condition between the constituent members 62 (62A to 62D) and the influence relationship such as thermal deformation change.
The shape of the structure model (FIG. 4) also changes sensitively to changes in these influence relationships. For this reason, if the construction order of the welding passes 61 (61A to 61L) is different, the shape of the final structure model is also greatly different.

Therefore, the result reflection unit 15 updates the shape of the structure model to the structure model construction unit 24 each time the first inherent strain 51 or the differential strain due to the single welding pass 61 is applied to the structure model. To instruct.
That is, as a result, if the number of constructions of the welding paths 61 (61A to 61L) is m, the reflection unit 15 performs shape update of the structure model m times.
Each time the shape of the structure model is updated, the result is output to the result display unit 16 using a contour diagram or the like.

Based on the flowchart of FIG. 5, a welding deformation analysis method and a welding deformation analysis program according to the embodiment will be described.
The joint model (FIG. 2) corresponding to the welding mode of the structural member 62 of the structure model (FIG. 4) and the welding path 61 is selected (S11). The material properties and welding conditions of the component members 62 to be welded to each other are input (S12). In addition, when the welding operation of these structural members 62 is performed n times, different welding conditions can be set for each welding operation.

First, in the first welding operation (S13), the first inherent strain 51 ₁ distributed in the welded portion (FIG. 3A) of the joint model is calculated (S14). Further, the second to nth inherent strains 51 distributed in the welded portion of the joint model are calculated by the respective welding operations up to the nth time (S15 Yes / No).

Based on the difference between the j-th intrinsic strain 51 _j and the j-1 intrinsic strain 51 _j-1 (2 ≦ j ≦ n), the differential strain in which the j-th welding operation is independently distributed in the welded part of the joint model And the differential strain and the first inherent strain 51 ₁ derived up to the n-th time are registered (S16).
Next, a plurality of welding passes 61 _k (1 ≦ k ≦ m) to be constructed in the structure model (FIG. 4) and their order are set (S17).

First, assuming a state where the welding pass 61 is not applied (k = 0) (S18), a structural model is constructed by combining the constituent members 62 (62A to 62D) (S19).
Then, the differential strain or the first inherent strain 51 ₁ corresponding to the execution of the welding pass 61 _k (1 ≦ k ≦ m) from the first to the m-th is acquired (S20), and applied to the structure model to execute the deformation analysis. (S21).
This analysis result is reflected in the structure model each time a single welding pass 61 _k is applied, and the shape of the structure model is updated (S22, S23 No / Yes, END).

  According to the welding deformation analysis apparatus of the embodiment described above, by applying the differential strain between the inherent strain formed by a plurality of welding operations and the inherent strain formed up to the previous welding operation, the database information Without increasing the amount, welding deformation analysis based on the inherent strain method can be performed with high accuracy.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, changes, and combinations can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  In addition, the constituent elements of the welding deformation analysis apparatus can be realized by a processor of a computer and can be operated by a welding deformation analysis program.

DESCRIPTION OF SYMBOLS 10 ... Welding deformation | transformation analysis apparatus, 11 (11a, 11b) ... Intrinsic strain calculating part (1st calculating part, 2nd calculating part, calculating part), 12 ... Differential strain derivation | leading-out part (derivation | leading-out part), 13 ... Registration part, 14 ... Analysis execution part, 15 ... Result reflection part, 16 ... Result display part, 21 ... Joint model selection part, 22 ... Welding condition input part, 23 ... Material property input part, 24 ... Structural model construction part, 25 ... Welding path Setting unit 51 (51 ₁ )... First intrinsic strain 51 ₁ , 51 (51 ₂ )... Second intrinsic strain 51 ₂ , 51 (51 _n )... N n intrinsic strain 51 _n , 53 (53 _{1 to} 53 ₆ ) ... weld _{pass, 61 (61A~61L), 61 k} ... weld pass, 62 (62A to 62D) ... components.

Claims (3)

a first computing unit that computes the n-1th inherent strain distributed in the welded part by n-1 times (n is a natural number of 2 or more) welding operation;
a second computing unit that computes the nth inherent strain distributed in the welded portion of the joint model welded by n welding operations;
A differential strain deriving unit for deriving a differential strain in which the n-th welding operation is independently distributed to the weld based on the difference between the n-th inherent strain and the n-1th inherent strain;
A registration unit for registering each of the first inherent strain and the differential strain up to the nth time in the joint model;
A structure model building unit for building a structure model to be subjected to deformation analysis;
A plurality of welding paths constructed in the structure model and a welding path setting unit for setting the order thereof;
An analysis execution unit that applies the first inherent strain or the differential strain corresponding to each welding path to the structure model and executes the deformation analysis;
A welding deformation analysis apparatus, comprising: a result reflection unit that reflects a result of the welding path construction and the deformation analysis on the structure model each time in the order of the construction. a step of calculating an n-1th inherent strain distributed in the weld by n-1 times (n is a natural number of 2 or more) welding operation;
calculating the nth inherent strain distributed in the weld of the joint model welded by n welding operations;
Deriving a differential strain that the n-th welding operation is independently distributed to the weld based on the difference between the n-th inherent strain and the n-1th inherent strain;
Registering each of the first inherent strain and the differential strain up to the nth time in the joint model;
Building a structure model for deformation analysis; and
Setting a plurality of welding paths and their order to be constructed in the structure model; and
Applying the first inherent strain or the differential strain corresponding to each welding path to the structure model and performing the deformation analysis;
Reflecting the result of the construction of the welding pass and the deformation analysis to the structure model in accordance with the order of the construction each time. On the computer,
a step of calculating the (n-1) th intrinsic strain distributed in the welded part by n-1 times (n is a natural number of 2 or more) welding operation;
calculating the nth inherent strain distributed in the weld portion of the joint model welded by n welding operations;
Deriving a differential strain in which the nth welding operation is independently distributed to the weld based on the difference between the nth inherent strain and the n-1th inherent strain;
Registering each of the first inherent strain and the differential strain up to the nth time in the joint model;
Building a structure model for deformation analysis;
A step of setting a plurality of welding passes to be constructed in the structure model and their order;
Applying the first inherent strain or the differential strain corresponding to each of the welding passes to the structure model to perform the deformation analysis;
A welding deformation analysis program for executing the step of reflecting the construction of the welding pass and the result of the deformation analysis in the structure model in accordance with the order of the construction each time.

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