Methods for determining the gelation period of a gel solution are provided. The methods provided include introducing a first inert ball, or first inert hollow ball comprising a polymer solution, into a gel solution container containing a gel solution where upon the first inert ball, or inert hollow ball, reaching a bottom of the gel solution container, at least one subsequent inert ball, or inert hollow ball, is introduced sequentially into the gel solution container until the at least one subsequent inert ball, or inert hollow ball remains fixed in place prior to reaching the bottom of the gel solution container. Methods also include determining the gelation time of the gel solution based on a sum of distances traveled by the first inert ball, or inert hollow ball, and at least one subsequent inert ball, or inert hollow ball.

Tool wear monitoring is critical for quality and precision of manufacturing of parts in the machining industry. Existing tool wear monitoring and prediction methods are sensor based, costly and pose challenge in ease of implementation. Embodiments herein provide method and system for monitoring tool wear to estimate Remaining Useful Life (RUL) of a tool in machining is disclosed. The method provides a tool wear model, which combines tool wear physics with data fitting, capture practical considerations of a machining system, which makes the tool wear prediction and estimated RUL more stable, reliable and robust. Further, provides cost effective and practical solution. The disclosed physics based tool wear model for RUL estimation captures privilege of physics of tool wear and easily accessible data from CNC machine to monitor and predict tool wear and RUL of the tool in real-time.

A steel pipe collapse strength prediction model generation method, a steel pipe collapse strength prediction method, a steel pipe manufacturing characteristics determination method, and a steel pipe manufacturing method capable of highly accurately predicting the collapse strength under external pressure bending of a coated steel pipe coated after steel pipe forming in consideration of the pipe-making strain during steel pipe forming and coating conditions as well as the bending strain during construction. Into a steel pipe collapse strength prediction model generated by the steel pipe collapse strength prediction model generation method, steel pipe manufacturing characteristics including the steel pipe shape of a coated steel pipe to be predicted after steel pipe forming, steel pipe strength characteristics after steel pipe forming, the pipe-making strain during steel pipe forming, coating conditions, and the bending strain during construction are input to predict the collapse strength under pressure bending of the coated steel pipe.

Methods for determining the gelation period of a gel solution are provided. The methods provided include introducing a first inert ball, or first inert hollow ball comprising a polymer solution, into a gel solution container containing a gel solution where upon the first inert ball, or inert hollow ball, reaching a bottom of the gel solution container, at least one subsequent inert ball, or inert hollow ball, is introduced sequentially into the gel solution container until the at least one subsequent inert ball, or inert hollow ball remains fixed in place prior to reaching the bottom of the gel solution container. Methods also include determining the gelation time of the gel solution based on a sum of distances traveled by the first inert ball, or inert hollow ball, and at least one subsequent inert ball, or inert hollow ball.

Proposed is an auto-flattening control method that is an auto-flattening control method for determining a minimum driving value of tension that is applied to a sample coupled at both sides to a moving unit and a winding unit, respectively. The auto-flattening control method includes a sample rotation step of rotating the winding unit at a preset reference angle, a setup value checking step of monitoring a rotation load that is applied to a sample by rotation of the winding unit, and a setting comparison step of comparing variations between an N-th (a natural number larger than 0) rotation load and an N-1-th rotation load for the rotation load that is monitored through the setup value checking step.

A method for determining characteristics of a crack detected in a material, comprising: determining initial mechanical loads applied to the material, applying a plurality of crack-opening mechanical loads to the material, each opening mechanical load being a linear combination of the initial mechanical loads, and measuring the relative displacement of the first point with respect to the second point induced by each opening mechanical load, applying a plurality of crack-closing mechanical loads to the material, each closing mechanical load being a linear combination of the initial mechanical loads, and measuring the relative displacement of the first point with respect to the second point induced by each closing mechanical load, and estimating the direction of the crack as a function of the amplitude of each opening and closing mechanical load applied to the material and of the measured relative displacements.

A stress-strain curve simulation method, for calculating a simulated stress-strain curve of a test object sandwiched between a mass block and a testing platform, the method comprises: obtaining a first acceleration curve associated with a plurality of pieces of acceleration data of the mass block and a second acceleration curve associated with a plurality of pieces of acceleration data of the testing platform; extracting a part of the first acceleration curve and a part of the second acceleration curve to obtain a first valid curve and a second valid curve; obtaining an object strain curve according to the first valid curve and the second valid curve; calculating an object stress curve based on the first valid curve and a contact area between the mass block and the test object; and calculating the simulated stress-strain curve based on the object strain curve and the object stress curve.

This patent studies a scale-span modeling method to simulate the structural mechanical responses and dynamic progressive failure behaviors of carbon fiber reinforced plastics (CFRPs) in drilling. Firstly, considering the different mechanical behaviors of fiber and matrix in micro state, a three-dimensional multi-scale dynamic progressive damage evolution model based on micro failure theory is proposed. Based on the degradation elastic parameters of microcomponent in typical volume element model, a new damage evolution model of fiber and resin matrix and an auxiliary deletion criterion of failure element are proposed. Secondly, the relationship between the macro stress and the micro stress of representative volume element in the composite model is established by using the stress amplification factor. Combined with the bilinear cohesion element model, the damage behavior of the composite in and between layers under the cutting action of dagger drill is simulated.

The objective of the present invention is to provide a hardness meter which estimates hardness in a stable manner regardless of a compression strength. A hardness meter includes: a movable portion which is continuously pressed against an object to be measured; a sensor which outputs an output signal reflecting a reaction force at a part of the object to be measured; a motive force mechanism that causes the movable portion to perform a piston motion; a hardness estimating portion which estimates the hardness of the object on the basis of an alternating current component of the output signal, generated by the piston motion; a position estimating portion which estimates a measurement position information by shooting with a camera; and a hardness map display portion which maps and displays the hardness on a schematic diagram of the surface of a living body based on the measurement position information.

Provided is a method for evaluating a hydrogen embrittlement fracture risk of an iron reinforcing bar that is performed by a hydrogen embrittlement fracture risk evaluation apparatus, the method including: a fracture probability curved surface generation step of obtaining a fracture probability curved surface representing a probability of the iron reinforcing bar fracturing by performing regression analysis on results obtained by repeatedly carrying out a hydrogen embrittlement test while changing an amount of hydrogen absorbed in the iron reinforcing bar provided in a concrete structure and a tensile stress applied to the iron reinforcing bar and using the amount of hydrogen and the tensile stress as variables; a lower limit stress acquisition step of acquiring, from the fracture probability curved surface, a lower limit stress property representing a relationship between a lower limit stress that is a lower limit of the tensile stress at which no fracture occurs in the iron reinforcing bar at a predetermined probability and the amount of hydrogen; and an evaluation step.