186results about "Investigating material ductility" patented technology

The invention relates to the technical field of titanium alloy detection, and discloses a titanium alloy wire performance detection method, equipment and system. The method comprises the following steps: acquiring real-time force value displacement data of a tensile test and echo signal data of ultrasonic detection, and processing to obtain smooth force value displacement data and spectrum characteristic parameters; performing feature layer fusion on the yield strength, the tensile strength, the peak frequency and the amplitude attenuation rate to construct a first multi-dimensional feature matrix; inputting a pre-trained deep belief network model, and predicting mechanical properties such as elongation and hardness value; and comparing with a preset threshold value, marking unqualified items and generating a detection report. According to the method, through multi-source data fusion and advanced algorithm processing, the comprehensiveness and accuracy of detection are improved, efficient evaluation of the performance of the titanium alloy wire is achieved, and the method is suitable for the strict detection requirements for the quality of the titanium alloy wire in the fields of aerospace, medical instruments and the like.

A method for identifying a necking limit strain of a metal sheet according to the present invention includes a step (S1) of measuring the distribution of strain in a tensile orthogonal direction in a tensile deformation process of a notch root 5a for two or more types of sheet specimens 1 having a notch geometry 5 in a portion of a sheet edge 3; a step (S3) of obtaining a strain increment ratio of the notch root 5a in the tensile deformation process and a strain gradient in the tensile orthogonal direction; a step (S5) of obtaining necking limit strain at which necking occurs in the notch root 5a based on the strain increment ratio in the tensile deformation process; and a step (S7) of identifying the necking limit strain as a function of the strain gradient from the relation between the necking limit strain obtained for the two or more types of sheet specimens 1 and the strain gradient at that time.

The invention provides a heat treatment-free aluminum alloy casting production process, and belongs to the technical field of alloys, and the heat treatment-free aluminum alloy casting production process comprises the following steps: S1, alloy preparation; s2, smelting and refining are conducted, after pure aluminum ingots are molten, heating and mixing are conducted, powder spraying refining and degassing treatment are conducted, and the dosage of a refining agent accounts for 0.1%-0.3% of the mass of molten liquid; s3, die-casting forming is conducted, specifically, a high-vacuum die-casting process is adopted, the injection pressure is 80-150 MPa, the melt pouring temperature is 680-720 DEG C, and the die preheating temperature is 150-250 DEG C; s4, natural aging treatment; the specific parameters of the adding amount of a refining agent, the injection pressure and the pouring temperature are optimized through a three-factor three-level orthogonal test, the optimal machining process parameters are determined to be 0.20% of the refining agent, 120 MPa of the injection pressure and 700 DEG C of the pouring temperature by detecting the tensile strength, the ductility and the hardness of the alloy, at the moment, the tensile strength of the alloy is improved to 389 MPa, the ductility is improved to 8.5%, and the hardness is improved to HV65.8; and compared with the alloy before optimization, the alloy is increased by 9.0%, 26.8% and 2.3% respectively.

The utility model discloses a multi-angle adjustable testing machine clamping device, and relates to the technical field of clamping devices. Comprising a bottom plate, symmetrically distributed moving seats are arranged over the bottom plate, rotating discs are rotationally arranged in the moving seats, a plurality of driving grooves distributed in an annular array are formed in the rotating discs, driving blocks are slidably arranged in the driving grooves, moving plates are fixedly arranged at one ends of the driving blocks, and fixed wheels are fixedly arranged at the ends, close to each other, of the moving plates; wherein driving rods are fixedly arranged at the ends, away from the fixed wheels, of the two moving plates, one end of each driving rod slidably penetrates through one side wall of the corresponding moving seat to be arranged outside, and a frame is fixedly arranged on the upper surface of the outer portion of the bottom plate. By driving the multiple fixing wheels to be tightly attached to the tail end of the cable, it can be ensured that the cable is clamped and fixed, the situation that the cable is loosened in the testing process is prevented, and the testing precision of the cable is improved.

The utility model provides a stretching head structure for a viscosity and toughness test of high-viscosity asphalt, which relates to the technical field of asphalt tests and comprises a sample container and a connecting sleeve, a connecting rod is inserted into the inner surface of the connecting sleeve, and the bottom of the connecting rod is fixedly connected with a stretching head body. According to the utility model, the stretching head body can be accurately aligned with the center of a sample container under the matching of the support frame, the positioning hole and the positioning rod, and the position of the connecting rod in the connecting sleeve can be adjusted under the matching of the spring, the limiting rod, the adjusting hole and the sliding rod, so that the position of the stretching head body is adjusted; by adopting clamping adjustment, the problem that threaded connection needs to be replaced after being used for multiple times is avoided, under the assistance of the semi-sphere and the arc-shaped groove, the contact area between the stretching head body and an asphalt sample is increased, a certain stress dispersion effect can be achieved in the stretching process, and therefore the testing accuracy and stability are improved.

The invention relates to the field of secondary aluminum ingot product finished product quality detection, in particular to a secondary aluminum ingot product finished product quality detection device which comprises a shell. A partition plate is fixed in the shell, a translation assembly is arranged below the partition plate, each clamping assembly is provided with a hardness detection assembly, and three flaw detection assemblies and three deformation detection assemblies corresponding to the three centering assemblies respectively are arranged in the shell. During detection, an extrusion head is recessed into the end face of an aluminum ingot block under the pushing action of a first spring, and when the aluminum ingot block deforms due to stretching, second sliding rods located on the upper side and the lower side of the aluminum ingot block extend under the action of a third spring. The resistance value between the second sliding rod after extending and the second lantern ring is compared with the initial resistance value to obtain the telescopic length of the second sliding rod after the aluminum ingot block is deformed, then the ductility of the aluminum ingot block after being stretched is obtained, and the effect of multi-aspect detection is achieved in a matched mode.

A press forming fracture judgment method according to the present invention acquires a forming limit of a metal sheet which limit is expressed by a relationship between a maximum principal strain and a minimum principal strain of a test piece 100 bulge formed at various bending deformation degrees and a bending deformation degree (P1), and determines presence or absence of fracture generation in a press formed part based on the acquired forming limit of the metal sheet and the maximum principal strain, the minimum principal strain, and the bending deformation degree which are calculated for a press formed part (P3).

The invention discloses a post-welding adjusting and repairing method for an aluminum alloy bracket of a railway vehicle. The post-welding adjusting and repairing method comprises the steps that the first deformation amount of a deformation position is measured; preparing a plurality of first tensile samples, and performing flame heating adjustment at a preset flame heating temperature; performing a tensile test on the first tensile sample; establishing a relationship between the mechanical property and the flame heating temperature, and obtaining a target flame heating temperature; manufacturing a second tensile sample, and performing deformation treatment and mechanical adjustment treatment for preset times; performing a tensile test on the second tensile sample, establishing a relationship between the mechanical property and the times of deformation treatment and mechanical adjustment treatment, and obtaining a target mechanical adjustment time; flame heating adjustment and mechanical adjustment are conducted on the aluminum alloy bracket according to the target flame heating temperature and the target mechanical adjustment frequency; and manufacturing a fatigue sample, carrying out a fatigue test, and evaluating the safety of adjustment and repair. According to the method, flame heating adjustment and mechanical adjustment are combined, welding residual stress can be released, and deformation deviation can be accurately corrected.

The present application relates to the technical field of cotton fiber detection. A kind of intelligent beam fiber strength tester, including cabinet, industrial computer, sliding table module is provided in cabinet, sectional material frame, air cylinder, beam fiber clamping mechanism, stepper motor, lever type pull rod, force sensor, displacement sensor, resistance detection plate, A / D acquisition conversion module;The application method of the tester, steps include: under normal environmental conditions, beam fiber clamping mechanism clamps fiber sample, obtains moisture regain R by resistance moisture regain conversion program conversion;Stepper motor drives lever type pull rod to stretch sample, data is made into the tensile curve F (e) of beam fiber sample-e by industrial computer, and machine learning model predicts the corrected breaking strength value and elongation rate.The present application is simple and reasonable in structure, can realize the quick and accurate measurement of cotton beam fiber breaking strength value and breaking elongation rate under different humidity conditions in normal environment, is high in informatization degree, economic and practical, and improves the accuracy of test result.

The utility model discloses a simple device for drawing a gauge length of an aluminum alloy circular performance sample, which belongs to the technical field of gauge lengths of aluminum alloy samples, solves the problems that the operation is difficult and the marking is easy to generate errors when the gauge length of the aluminum alloy circular performance sample is manually made at present, and comprises a caliper bracket, a sample bracket and a caliper, a sliding rail is arranged on a caliper support bottom plate, vertical groove-shaped caliper support supporting rods are symmetrically arranged on the two sides of the bottom plate, spring columns are arranged at the bottoms in grooves of the caliper support supporting rods, and springs are arranged on the spring columns. A left sample holder supporting rod and a right sample holder supporting rod of the sample bracket are arranged on the slide rail in a sliding manner; the caliper is provided with a fixed measuring claw and a caliper outer measuring claw in a sliding mode, two sides of the caliper are lengthened to be provided with blank caliper bodies, and two ends of the blank caliper bodies are clamped in the caliper support supporting rod grooves in a sliding mode and abut against the tops of the springs. The marking of various scale distances is accurately realized, and the efficiency and the accuracy of marking the scale distances are greatly improved.

The application relates to the technical field of titanium alloy detection, and discloses a titanium alloy wire performance detection method, equipment and system. The method collects real-time force value displacement data of a tensile test and echo signal data of ultrasonic detection, obtains smooth force value displacement data and frequency spectrum characteristic parameters after processing, fuses yield strength and tensile strength with peak frequency and amplitude attenuation rate in a characteristic layer, and constructs a first multi-dimensional characteristic matrix; the method inputs a pre-trained deep confidence network model, predicts mechanical properties such as elongation and hardness value, compares with a preset threshold value, marks unqualified items, and generates a detection report. The method improves the comprehensiveness and accuracy of detection through multi-source data fusion and advanced algorithm processing, realizes efficient evaluation of titanium alloy wire performance, and is suitable for strict detection requirements of titanium alloy wire quality in the fields of aerospace, medical devices and the like.

A method for the assessment of the irradiation embrittlement in a nuclear reactor pressure vessel RPV (10) comprises the steps (a): cutting a specimen (20, 40) from an un-irradiated RPV (10); (b): measuring grain size Dg of each grain (30) on a region (21, 41) of the specimen (20, 40); (c): performing several indentation tests at a temperature on this region; (d) to (g): for each test, calculating for each grain (30) the slip band number density N / Dg from equations; (h): repeating steps (c) to (g) at different temperatures to obtain an un-irradiated curve around the ductile-brittle transition temperature DBTT; (i): submitting specimen (40) to an irradiation dose and repeating steps (b) to (g) at different temperatures to obtain an irradiated curve around the DBTT; (j) and (k): assessing the irradiation embrittlement in the RPV from the ductile-brittle transition shift between the un-irradiated and irradiated curves.

The utility model relates to the technical field of battery pole piece production, and discloses a pole piece elongation measuring device which comprises a measuring platform, a first pressing mechanism and a second pressing mechanism. The measuring platform is provided with a groove which is a straight groove. The first pressing mechanism is arranged on one side of the groove and can press the coating area of the pole piece to be measured on the measuring platform; the second pressing mechanism is arranged on the other side of the groove and can press the tab area of the pole piece to be measured on the measuring platform; a clearance area is formed between the first pressing mechanism and the second pressing mechanism and corresponds to the groove, so that the coating area and the tab area of the to-be-detected pole piece can be cut along the groove through the cutting mechanism. The device for measuring the extension rate of the pole piece solves the problems that the measurement of the extension rate of the pole piece fails due to the breakage of the pole piece, the extension rate of the pole piece needs to be measured again, the scrappage of the pole piece is increased, and the measurement efficiency of the extension rate of the pole piece is low.

The utility model discloses a steering wheel leather piece stretching, matching and grading automation device which comprises a support. A servo motor, a ball screw, a stretching guide rail, a fixed lower clamp, a first shell and a second shell are installed on the support. A movable table top is slidably connected to the stretching guide rail and sequentially connected with a ball screw and a servo motor. The movable table top is connected with the movable lower clamp and the movable upper clamp assembly, and the movable lower clamp is located under the movable upper clamp assembly. A fixed upper clamp assembly is arranged over the fixed lower clamp and connected with the first shell. A touch screen and a gear indicator lamp are arranged on the shell I; and a warning lamp, an emergency stop knob and a start button are arranged on the shell II. According to the utility model, the elongation value of the leather grafts can be directly measured, whether products meet requirements can be directly judged, the leather grafts meeting the elongation value range are delivered as qualified products, and the leather grafts exceeding the elongation value range are screened out and discarded.

The invention provides an asphalt extensibility detection device for highway construction, which comprises a supporting plate, the top of the supporting plate is provided with a bath, the supporting plate is provided with a fixed pulling frame and a movable pulling frame, the middle parts of the fixed pulling frame and the movable pulling frame extend into the bath, and the supporting plate is provided with a stretching driving mechanism for driving the movable pulling frame to be far away from or close to the fixed pulling frame. A convex lens assembly is arranged in the middle between the fixed pull frame and the movable pull frame and is in transmission connection with the movable pull frame through a lens linkage mechanism; according to the device, the two ends of a manufactured test mold are installed on the top of the movable pulling frame and the top of the fixed pulling frame respectively, the stretching driving mechanism drives the movable pulling frame to move to stretch an asphalt sample in the test mold, and in the moving process of the movable pulling frame, the lens linkage mechanism drives the convex lens assembly to move; the convex lens assembly and the middle part of the stretched sample are kept in a corresponding state, so that the asphalt drawn wire is amplified, and changes such as fracture, bending or drooping of the asphalt drawn wire can be found in time.

The present invention discloses a method for monitoring the aging degree of in-service SBS modified asphalt pavement, which includes the following steps: (1) Conduct a simulated aging test on the SBS modified asphalt used for paving the road surface, conduct a force-elongation test and a Fourier transform infrared spectroscopy test on the SBS modified asphalt with different aging times, establish a S BC relationship curve with A 1700 / 1600 , and calculate the S BC when it is 0, denoted as A 1700 / 1600 , denoted as A 0; (2) During the service process of the road surface, regularly drill core samples of the asphalt surface layer, extract and recover the in-service SBS modified asphalt from the upper and middle surface layers respectively, conduct a Fourier transform infrared spectroscopy test, and calculate the A 1700 / 1600 of the upper and middle surface layers respectively according to the infrared spectra; (3) Evaluate the aging degree of the in-service SBS modified asphalt pavement based on the relationship curve between S BC and A 1700 / 1600 . The present invention provides a method for monitoring the aging degree of in-service SBS modified asphalt pavement, which can provide a basis and tool for the decision-making of the maintenance timing and maintenance plan of SBS modified asphalt pavement.

To predict a value related to the ductility of a ferrous material correctly.SOLUTION: A ductility estimation device comprises: an image acquisition unit which acquires a plurality of images of a ferrous material photographed so as to have different magnifications; a feature amount extraction unit which extracts feature amounts from the plurality of images; an estimation unit which estimates a value related to the ductility of the ferrous material by inputting the feature amounts to an estimation model that has learned so as to output the value related to the ductility of the ferrous material with the feature amounts of the images expressing the ferrous material photographed at the different magnifications as input; and an estimation result output unit which outputs the estimation result.SELECTED DRAWING: Figure 1

A bond test apparatus (200, 350) comprises: a test tool assembly, the test tool assembly comprising a test tool configured to contact a bond (101) during a bond test; a flexure (80, 380) coupled to the test tool assembly; a displacement sensor (220, 425); and a detectable member (110, 415). One of the detectable member and the displacement sensor is fixed relative to a first end of the flexure and the other is fixed relative to a second end of the flexure. The displacement sensor is not a strain gauge. The displacement sensor is configured to detect a displacement between the displacement sensor and the detectable member, so that the displacement sensor provides a measurement of a displacement of the first end of the flexure relative to the second end of the flexure on application of a force to the flexure. The bond test apparatus comprises a processor configured to receive a displacement signal from the displacement sensor and to determine the force on the flexure using the displacement signal. A cartridge for a bond test apparatus, a method of measuring a force in a bond test apparatus, and a method of measuring the closing force on the jaws of a bond test tool are also provided.

The application discloses a method for setting rolling parameters in a lithium battery pole piece rolling process, which comprises the following steps: based on the process standard of the pole piece appearance and the wave edge height, rolling tests are carried out on the pole piece under different compaction densities to verify the relationship between the elongation of the material area and the elongation of the tab blank area and the tab dispensing area, and the ratio relationship between the elongation of the material area and the elongation of the tab blank area and the tab dispensing area under different compaction densities is determined; different elongation roller coating layer thicknesses and different stretching force values are set on the elongation roller to carry out elongation tests on the pole piece, the relationship between the elongation roller coating layer thickness and the stretching force value and the elongation of the pole piece blank is verified, and a fitting formula and an isogram of the elongation of the pole piece blank and the elongation roller coating layer thickness and the elongation stretching force value are obtained; based on the ratio relationship and the fitting formula, the stretching force value and the elongation roller coating layer thickness under the preset compaction density of the pole piece are calculated, and the isogram is verified.

The present invention provides a technology that enables easy and accurate acquisition of material properties that affect the dimensional accuracy of presses, even within a press line.The method for acquiring material properties of a metal plate for press working involves performing a stretching process on the metal plate, measuring the forming load and die stroke during the stretching process, and measuring the thickness of the metal plate, and then determining the yield stress of the metal plate from the measured forming load, die stroke, and thickness.

To provide a molding limit decision method for metal plate, a molding limit decision system for metal plate and a molding limit decision program for metal plate that can conduct a molding test on a test piece of a metal plate to precisely decide the molding limit of the metal plate.SOLUTION: A molding limit decision method for metal plate includes: constructing a database by molding a metal plate while consecutively photographing a surface of a test piece 101 and measuring strains generated on the surface of the test piece 101 from the start of the molding until fracture and three-dimensional coordinates on the surface of the test piece 101 (S10); setting an evaluation point array along a fracture orthogonal direction orthogonal to a fracture part 103 generated in the test piece 101 and extracting strains or three-dimensional coordinates of the evaluation point array from the database (S20); and calculating a fracture orthogonal-directional gradient of the strains or three-dimensional coordinates of the evaluation point array to decide a molding limit (S30).SELECTED DRAWING: Figure 1

The invention provides a method for evaluating the crack resistance of an asphalt mixture, which comprises the following steps: testing the low-temperature performance of a preset modified asphalt material to obtain the low-temperature performance A of the modified asphalt material. A preset stone material is graded with a preset modified asphalt material, and the asphalt mixture is prepared. And testing the low-temperature performance of the asphalt mixture to obtain the low-temperature performance B of the asphalt mixture. Comprehensively evaluating the crack resistance Q of the asphalt mixture based on the low-temperature performance A of the modified asphalt material and the low-temperature performance B of the asphalt mixture. According to the invention, a plurality of low-temperature performance tests from the asphalt material to the asphalt mixture are designed according to special climate and geological characteristics of areas with severe environments, so that the crack resistance of the asphalt mixture is accurately evaluated.

The utility model provides macromolecule waterproof roll ductility detection equipment, and belongs to the technical field of waterproof roll ductility detection. The high polymer waterproof roll ductility detection equipment comprises a processing table, the top of the processing table is provided with a fixed seat, the fixed seat is internally provided with a mounting frame, the mounting frame is internally provided with a hydraulic cylinder, the bottom of the hydraulic cylinder is provided with a limiting plate, a displacement sensor is arranged above the processing table, and the displacement sensor is connected with the hydraulic cylinder. The waterproof roll body, the limiting plate, the limiting fence, the threaded rod, the electric push rod, the pressing block, the hydraulic cylinder and the displacement sensor are matched with one another, the electric push rod is started to drive the pressing block to move downwards, the waterproof roll body can be preliminarily limited, the hydraulic cylinder is started to drive the limiting plate to move downwards, and therefore the waterproof roll body can be fixed. And the displacement sensor is started, so that the waterproof coiled material main body can extend, the waterproof coiled material main body can be prevented from sliding off, and the detection effect is improved.

The utility model discloses a stretching and bending test all-in-one machine for cable detection, and relates to the technical field of cable detection. The device comprises a detection bench, four corners of the top of the detection bench are fixedly connected with supporting legs, and the center of the bottom of the detection bench is provided with an adaptive groove. According to the cable bending detection device, a rotating rod is arranged, specifically, a second motor is controlled and started to drive a second output rod, the rotating rod is made to rotate through a second crawler belt, so that bending detection of a cable is completed, meanwhile, a first motor drives a first output rod to rotate, and a first crawler belt drives a threaded rod to make a second protection box move back and forth on a sliding rail in a reciprocating mode; the extensibility of the detection equipment can be tested, a worker controls the action direction and the action position of a machine through a program file in the data display console and monitors the on-off condition of each circuit at the same time, data fed back by the equipment are collected in a unified mode, then the data are recorded rapidly and effectively, and the detection efficiency of the equipment is improved.

In a metal plate molding limit determination method according to the present invention: a surface of a test piece 101 is molded while being sequentially images, and a strain on the surface of the test piece 101, which is generated from the start of molding to a point at which fracture occurs, as well as three-dimensional coordinates of the surface of the test piece 101, are measured to construct a database (S10); an evaluation point string is set along a fracture orthogonal direction that is orthogonal to a fractured section 103 generated in the test piece 101, and strain or three-dimensional coordinates in the evaluation point string are extracted from the database (S20); and a fracture orthogonal direction gradient of the strain or the three-dimensional coordinates in the evaluation point string is calculated, and a molding limit is determined (S30).

The invention belongs to the technical field of steel product quality management, and particularly relates to a method and a system for realizing automatic conversion of percentage elongation after fracture of a steel product, which are characterized in that the method is a material test item conversion subprogram in an existing manufacturing system quality management program. Firstly, automatic comparison of sample size codes in a tensile test item is carried out, and when the sample size codes of materials actually subjected to a tensile test are inconsistent with the sample size codes required by a contract, automatic conversion of after-fracture elongation values can be carried out after confirmation of technicians. The method has the beneficial effects that the existing quality system processing logic is perfected by taking the national standard GBT-17600.1 as the benchmark, the automatic conversion of the percentage elongation after fracture as required is realized, the method for automatically judging the quality of a real object and printing a quality guarantee book according to the converted data can be completed, and the occupation of test resources and the material waiting time are greatly reduced.

The invention discloses asphalt extensibility detection equipment for highway construction, and relates to the technical field of asphalt extensibility detection. According to the asphalt extensibility detection equipment for road construction, through cooperation of a positioning sleeve rod and a sliding rod, after an asphalt sample is prepared, gas can be filled into the positioning sleeve rod through operation of a negative pressure device, so that side edge templates on the two sides and a bottom supporting plate are automatically separated from the asphalt sample; then, the asphalt sample moves downwards along with the movable frame and the fixed frame to be immersed into water, the extension degree of the asphalt sample is detected, compared with a traditional detection mode, the mold and the asphalt sample can be automatically separated, the immersion experiment and the extension degree experiment are sequentially conducted, and the operation convenience and the operation efficiency of the equipment are further improved.

Methods for determining surface loads, deformations on forming machines and / or the quality of a formed workpiece, in which with at least one forming tool (1) which is force-fitted to a force transmission element (3) of a forming machine or to a table of a forming machine, a mechanical forming force is applied to a workpiece to be processed during a forming process, which causes a surface load and / or a deformation on at least one contact surface (5) between the at least one forming tool (1) and the force transmission element (3) or between the at least one forming tool (1) and the table, and with at least one sensor (4) designed to detect a physical quantity and attached in or on the tool clamping element (2) at a defined position, detects at least one physical quantity in or on the tool clamping element (2) and transmits measurement data of the at least one physical quantity to an electronic evaluation device, and in the electronic evaluation device the surface load on the at least one contact surface (5) and / or the deformation of the at least one contact surface (5) is determined depending on the respective position and the measurement data of the at least one sensor (4) and / or the quality of a workpiece formed in the process is determined; wherein the surface load and / or deformation of the contact surface (5) is / are determined with an evaluation model with which the measurement data of the at least one sensor (4) for a known position of the at least one sensor (4) in or on the tool clamping element (2) is mathematically mapped to the surface load and / or deformation of the contact surface (5) or the quality is determined by the course of at least one recorded physical quantity as a function of time or of the distance traveled during the forming process of at least one forming tool (1).

A fracture determination method in a press forming analysis according to the present invention determines a fracture of a blank in the press forming analysis on the basis of a forming limit diagram, and includes: measuring a distance between each of shell elements of the blank and each of an upper die and a lower die at a tool position where fracture determination is performed (S1); setting a shorter one of the distances to the upper die and the lower die as a tool distance of each of the shell elements (S3); determining that the shell element in which the tool distance is 1 / 2 or less of a sheet thickness is in contact with the tool (S5); and determining presence or absence of the fracture for each of the shell elements by using the forming limit diagram acquired by the Nakajima test for the shell element determined to be in contact with the tool and using the forming limit diagram acquired by the Marciniak test for the shell element not determined to be in contact with the tool (S7).