Viscosity coefficient calculation device, indentation test device, tensile testing device, viscosity coefficient calculation method and program

Patent metadata

Field	Value
Publication number	US-10184865-B2
Application number	US-201415030597-A
Country	US
Kind code	B2
Filing date	Oct 3, 2014
Priority date	Oct 22, 2013
Publication date	Jan 22, 2019
Grant date	Jan 22, 2019

Abstract

A viscosity coefficient calculation device includes a resistivity acquiring part that acquires, for each plurality of periods of time until a specific strains is generated when a load is applied to a sample, a value of deformation resistivity corresponding to an apparent modulus of elasticity when modulus of elasticity considered to be in accordance with Hook's law, and an output part that outputs a value of a viscosity coefficient of the sample from the value of the deformation resistivity for the each plurality of periods of time acquired by the resistivity acquiring part using a relational expression associating the deformation resistivity with the viscosity coefficient, the relational expression being a fractional function for periods of time, the relational expression analytically obtained by substituting the deformation resistivity into a first order differential equation for a stress and a strain obtained from a configuration expression of a viscoelasticity model.

First claim

What is claimed is:

1. A viscosity coefficient calculation device, comprising:
a resistivity acquiring pert that acquires, when a load is applied to a sample, a value of deformation resistivity corresponding to an apparent modulus of elasticity when modulus of elasticity considered to be in accordance with Hook's law for each plurality of periods of time until a specific strain is generated; and
an output part that outputs a value of viscosity coefficient of the sample from the value of the deformation resistivity for the each plurality of periods of time acquired by the resistivity acquiring part using a relational expression that associates the deformation resistivity with a viscosity coefficient, the relational expression being a fractional function for periods of time, the relational expression analytically obtained by substituting the deformation resistivity to a first order differential equation for a stress and a strain obtained from a configuration expression of a viscoelasticity model.

2. The viscosity coefficient calculation device according to claim 1 , wherein
the viscoelasticity model is a three-element solid model.

3. The viscosity coefficient calculation device according to claim 1 , further comprising:
a load acquiring part that acquires, respectively corresponding to a plurality of rates at which loads are applied to the sample, a plurality of the loads and a plurality of one of indentation amounts and tensile amounts of the sample relative to the loads; and
a resistivity calculation part that calculates a value of the deformation resistivity for the each plurality of periods of time from the one of the indentation amounts and the tensile and the loads amounts acquired by the load acquiring part, and outputs the value to the resistivity acquiring part.

4. The viscosity coefficient calculation device according to claim 1 , wherein
the output part has:
a storage part that stores the relational expression; and
a viscosity calculation part that calculates a value of viscosity coefficient of the sample by acquiring the value of the deformation resistivity for the each plurality of periods of time from the resistivity acquiring part and referring to the relational expression stored- in the storage part.

5. An indentation test device, comprising:
an indentation part that indents an indenter into a sample;
a load acquiring part that acquires, when the indenter is indented by the indentation part at rates different from each other, a plurality of loads of the indenter and indentation amounts of the sample relative to the loads corresponding to a plurality of the rates;
a resistivity calculation part that calculates from the plurality of the loads and the indentation amounts acquired by the load acquiring part a value of deformation resistivity corresponding to an apparent modulus of elasticity when modulus of elasticity considered to be in accordance with Hook's law for each plurality of periods of time by an expression based on Hertz's theory of elastic contact; and
an output part that outputs a value of viscosity coefficient of the sample from the value of the deformation resistivity for the each plurality of periods of time calculated by the resistivity calculation part using a relational expression associating the deformation resistivity with the viscosity coefficient, the relational expression being a fractional function for periods of time, the relational expression analytically obtained by substituting the deformation resistivity into a first order differential equation for a stress and a strain obtained from a configuration expression of a viscoelasticity model.

6. A tensile testing device, comprising:
a pulling part that pulls a sample;
a load acquiring part that acquires, when the sample is pulled by the pulling part at a plurality of rates different from each other, a plurality of tensile loads and tensile amounts of the sample relative to the loads corresponding to the plurality of the rates;
a resistivity calculation part that calculates a value of deformation resistivity corresponding to an apparent modulus of elasticity when modulus of elasticity considered to be in accordance with Hook's law for each plurality of periods of time from the plurality of the loads and the tensile amounts acquired by the load acquiring part based on Hertz's theory of elastic contact; and
an output part that outputs a value of viscosity coefficient of the sample from the value of the deformation resistivity for the each plurality of periods of time calculated by the resistivity calculation part using a relational expression associating the deformation resistivity with the viscosity coefficient, the relational expression being a fractional function for periods of time, the relational expression analytically obtained by substituting the deformation resistivity into a first order differential equation for a stress and a strain obtained from a configuration expression of a viscoelasticity model.

7. A viscosity coefficient calculation method comprising:
acquiring, when a load is applied to a sample, a value of deformation resistivity corresponding to a modulus of elasticity when modulus of elasticity considered to he in accordance with Hook's law for each plurality of periods of time until a specific strain is generated; and
outputting a value of viscosity coefficient of the sample from the acquired value of the deformation resistivity for the each plurality of periods of time using a relational expression associating the deformation resistivity with the viscosity coefficient, the relational expression being a fractional function for periods of time, the relational expression analytically obtained by substituting the deformation resistivity to a first order differential equation for a stress and a strain obtained from a configuration expression of a viscoelasticity model.

8. A non-transitory computer readable medium having a program embodied therewith, the program executable by a computer to cause the computer to perform operations comprising:
acquiring, for each plurality of periods of time until a specific strain is generated when a load is applied to a sample, a value of deformation resistivity corresponding to an apparent modulus of elasticity when modulus of elasticity considered to be in accordance with Hook's law; and
outputting a value of viscosity coefficient of the sample from the acquired value of the deformation resistivity for the each plurality of periods of time using a relational expression associating the deformation resistivity with the viscosity coefficient, the relational expression being a fractional function for periods of time, the relational expression analytically obtained by substituting the deformation resistivity into a first order differential equation For a stress and a strain obtained from a configuration expression of a viscoelasticity model.

9. The viscosity coefficient calculation device according to claim 1 , wherein
the relational expression that associates the deformation resistivity with a viscosity coefficient is

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Assignees

• National Univ Corporation Tokyo Univ Of Agriculture And Technology
• National Univ Corporation Tokyo Un

Inventors

• Sakuma Atsushi
• Sango Yuma

Classifications

• G01N3/08 Primary

  by applying steady tensile or compressive forces (G01N3/28 takes precedence) · CPC title

• G01N2203/0094

  Visco-elasticity · CPC title

• G01N11/10

  by moving a body within the material · CPC title

• G01N3/42 Primary

  by performing impressions under a steady load by indentors, e.g. sphere, pyramid (G01N3/54 takes precedence) · CPC title