In a breaking prediction method of predicting a breaking portion of a component, which is obtained by forming a metal sheet, by using a finite element method, the breaking portion is easily and reliably extracted. This breaking prediction method includes a first step of performing forming analysis by using a finite element method in each of a case where the metal sheet is divided on the basis of a first mesh coarseness and a case where the metal sheet is divided on the basis of a second mesh coarseness which is coarser than the first mesh coarseness, a second step of obtaining a maximum main stress for each mesh in each of the case of the first mesh coarseness and the case of the second mesh coarseness, and a third step of obtaining a difference value between the maximum main stress in the case of the first mesh coarseness and the maximum main stress in the case of the second mesh coarseness in each portion of the component, and extracting a portion in the case of the first mesh coarseness, which corresponds to a portion in which the difference value is larger than a predetermined value, as the breaking portion.

In a breaking prediction method of predicting a breaking portion of a component, which is obtained by forming a metal sheet, by using a finite element method, the breaking portion is easily and reliably extracted. This breaking prediction method includes a first step of performing forming analysis by using a finite element method in each of a case where the metal sheet is divided on the basis of a first mesh coarseness and a case where the metal sheet is divided on the basis of a second mesh coarseness which is coarser than the first mesh coarseness, a second step of obtaining a maximum main stress for each mesh in each of the case of the first mesh coarseness and the case of the second mesh coarseness, and a third step of obtaining a difference value between the maximum main stress in the case of the first mesh coarseness and the maximum main stress in the case of the second mesh coarseness in each portion of the component, and extracting a portion in the case of the first mesh coarseness, which corresponds to a portion in which the difference value is larger than a predetermined value, as the breaking portion.

A rigidity measurement apparatus is a rigidity measurement apparatus that measures rigidity of an object to be measured and includes a load estimator, a displacement calculator, and a rigidity calculator. The load estimator estimates a load applied to a measurement point set on the object to be measured by using a captured image of the object to be measured. The displacement calculator calculates a displacement of the measurement point by using the captured image. The rigidity calculator calculates the rigidity of the object to be measured by using the load and the displacement.

A rigidity measurement apparatus is a rigidity measurement apparatus that measures rigidity of an object to be measured and includes a load estimator, a displacement calculator, and a rigidity calculator. The load estimator estimates a load applied to a measurement point set on the object to be measured by using a captured image of the object to be measured. The displacement calculator calculates a displacement of the measurement point by using the captured image. The rigidity calculator calculates the rigidity of the object to be measured by using the load and the displacement.

An improved apparatus and method for fillet punch creep testing of a small specimen comprises, in one implementation, a testing unit secured to a top end and a bottom end of a structural support unit, and configured to conduct creep testing on a specimen. The testing unit includes a loading unit, a fillet punch unit, a thermal unit, and a measuring unit. A filleted punch of the fillet punch unit transfers an applied pressure from the loading unit to the specimen clamped between an upper die and a filleted lower die of the fillet punch unit while the thermal unit surrounds the fillet punch unit, and heats the specimen during testing. The optimized filleted edges on the filleted punch and the filleted lower die eliminate stress concentration against the specimen resulting in stable measurements, and thus, reduce the dispersion of applied load during creep testing. Finally, an application of a constant load on the filleted punch prevents dispersion in the measured data being analyzed by the measuring unit, and allows creep testing to be repeated to predict a remaining life of in-service parts of a system.

An improved apparatus and method for fillet punch creep testing of a small specimen comprises, in one implementation, a testing unit secured to a top end and a bottom end of a structural support unit, and configured to conduct creep testing on a specimen. The testing unit includes a loading unit, a fillet punch unit, a thermal unit, and a measuring unit. A filleted punch of the fillet punch unit transfers an applied pressure from the loading unit to the specimen clamped between an upper die and a filleted lower die of the fillet punch unit while the thermal unit surrounds the fillet punch unit, and heats the specimen during testing. The optimized filleted edges on the filleted punch and the filleted lower die eliminate stress concentration against the specimen resulting in stable measurements, and thus, reduce the dispersion of applied load during creep testing. Finally, an application of a constant load on the filleted punch prevents dispersion in the measured data being analyzed by the measuring unit, and allows creep testing to be repeated to predict a remaining life of in-service parts of a system.

Apparatus and methods of evaluating brittleness by measuring force applied to an electrode specimen by simulating a wound state of a jelly-roll type electrode assembly are disclosed herein. In an embodiment, a brittleness evaluation apparatus includes a jig unit, a driving unit, and a measurement analyzing unit. The jig unit includes two jigs, a groove formed between the jigs, a pressing plate, and guides. The jigs facing each other and have top surfaces formed in a horizontal plane and configured to receive a specimen arranged on the top surfaces along a length direction extending between and along the top surfaces. The pressing plate is arranged perpendicular to the length direction and configured to cause the specimen to bend by descending into the groove. The guides are located on each of the top surfaces of the jigs and configured to prevent distortion of the specimen during descent of the pressing plate.

Apparatus and methods of evaluating brittleness by measuring force applied to an electrode specimen by simulating a wound state of a jelly-roll type electrode assembly are disclosed herein. In an embodiment, a brittleness evaluation apparatus includes a jig unit, a driving unit, and a measurement analyzing unit. The jig unit includes two jigs, a groove formed between the jigs, a pressing plate, and guides. The jigs facing each other and have top surfaces formed in a horizontal plane and configured to receive a specimen arranged on the top surfaces along a length direction extending between and along the top surfaces. The pressing plate is arranged perpendicular to the length direction and configured to cause the specimen to bend by descending into the groove. The guides are located on each of the top surfaces of the jigs and configured to prevent distortion of the specimen during descent of the pressing plate.

Method for characterizing a material (10), characterized in that it comprises the steps of carrying out a bending test and calculating a cross-section moment, M of said material (10) using the following equation: $M=\frac{F.Math.L_m\left({}_1\right)}{2.Math.{\cos }^2\left({}_1\right)}$
where F is the applied bending force, L.sub.m (.sub.1) is the moment arm, and .sub.1 is the bending angle. The expression for the moment, M, fulfils the condition for energy equilibrium:
Fds=2Md.sub.2
when the true bending angle, .sub.2 is: ${}_1-\frac{t.Math.\sin \left({}_1\right)}{L_m}d{}_1.$

Method for characterizing a material (10), characterized in that it comprises the steps of carrying out a bending test and calculating a cross-section moment, M of said material (10) using the following equation: $M=\frac{F.Math.L_m\left({}_1\right)}{2.Math.{\cos }^2\left({}_1\right)}$
where F is the applied bending force, L.sub.m (.sub.1) is the moment arm, and .sub.1 is the bending angle. The expression for the moment, M, fulfils the condition for energy equilibrium:
Fds=2Md.sub.2
when the true bending angle, .sub.2 is: ${}_1-\frac{t.Math.\sin \left({}_1\right)}{L_m}d{}_1.$