Eval 7 - Residual Stress Measurement · Eval 7: residual stresses calculation by the hole-drilling method Several theoretical models have been developed by many research centers in

SINT Technology s.r.l. Tel: +39.055.8826302 · Fax: +39.055.8826303 · [email protected] · www.sintechnology.com

Eval 7

Residual stress analysis software


Main features

Eval 7: residual stresses calculation by the hole-drilling method

Several theoretical models have been developed by many research centers in order to evaluate the residual stress

field produced by the strains measured by a strain gage rosette. Some of them (standard ASTM E837-08, Integral

method and Differential method) were already introduced in the standard version of the EVAL 6 software for the

calculation of residual stresses by the hole drilling method.

In the EVAL 7 software, the standard algorithms are improved with additional

features and a better graphical overview including a further database of strain

gage rosettes and materials.

Moreover, a new theoretical algorithm, named HDM, has been implemented:

this model is able to provide a further analysis of the residual stress field that

improves even more the standard residual stress analysis.

The HDM method is an evolution of the standard algorithms that provides

equivalent results to the Integral and ASTM method with a more powerful

calculation process and with the possibility to correct the main sources of

uncertainty of this method: the eccentricity and the local plasticity errors.

The new graphical layout with the upper control panel makes easy, intuitive and sequential process: all these new

features make the software EVAL 7 an essential tool for your analysis.

At last, the EVAL 7 software is fully compliant to the new version of the ASTM E837-13a standard.

Available methods for stress analysis:

ASTM E837-13a for uniform stress field

ASTM E837-08 for uniform stress field

Through hole stress evaluation with local

plasticity correction

ASTM E837-13a for non uniform stress field

Integral Method

Differential method

HDM method

Internal strain gage and material database

Measurement filtering for an optimal reduction

of measurement disturbs effects

Off axis hole drilling correction

Tikhonov regularization

High level 2D and 3D postprocessing tools for an

easier analysis of the stress field

Automatic test report

Direct interface with SINT Technology hardware

for hole drilling (RESTAN-MTS3000 system)

New graphic layout

Eval 7 Residual Stress Analysis Software


During the preprocessing stage, the software

supports the user by means of a predefined

and updated database of material properties

and commercial strain gage geometries in

order to allow a fast and reliable definition of

the test conditions.


Several output formats are available for an accurate analysis of the calculated stress field:

Preprocessing

Stress calculation

During the stress calculation stage, the software provides

the user with the most updated methods for stress

evaluation (ASTM E837-13a, ASTM E837-08, Differential

method, Integral method and HDM method) for an

accurate back-calculation of the stress field.

Advanced tools are available for the correction of the errors

due to casual off axis drilling or plasticity conditions.

Moreover, numerical regularizations of the stress field are

available in order to compensate ill-conditioned configurations:

in particular, the Tikhonov’s correction and the least square

method. Automatic optimal choice of the analysis parameters

is also available whenever required.

Postprocessing

Standard direct plot of principal stresses

and principal angle vs hole depth in the

thickness

3D views of the Mohr’s circles of the stress

field vs depth, with the possibility to focus

on particular positions into the thickness

for a more detailed investigation

Direct calculation of the stress components

according to the requested directions with

reference to the strain gage rosette

Automatic test report in html and txt format

Moreover, the user can take advantage of improved tools provided in

order to filter the possible measurement disturbances and to minimize

their effect on the final result. The choice of the filtering parameters

can be done manually or automatically by means of the optimization

routine implemented in the HDM calculation program for this purpose.


ASTM E 837-13a, “Standard Test Method for Determining Residual Stresses by the Hole-Drilling Strain-Gage

Method”

ASTM E 837-08, “Standard Test Method for Determining Residual Stresses by the Hole-Drilling Strain-Gage

Method”

Schajer, G. S., “Measurement of Non-Uniform Residual Stresses Using the Hole-Drilling Method. Part I - Stress

Calculation Procedures”, Journal of Engineering Materials and Technology, Vol. no. 110, 1988, pages 338-343

Schajer, G. S., “Measurement of Non-Uniform Residual Stresses Using the Hole-Drilling Method. Part II - Practical

Application of the Integral Method”, Journal of Engineering Materials and Technology, Vol. no. 110, 1988, pages

344-349

Schwarz, T., Kockelmann, H., “The hole-drilling method - the best technique for the experimental determination

of residual stresses in many fields of application”, MTB 29, 1993, Vol. no. 2, pages 33-38

Beghini M., Bertini L., Rosellini W., “Genetic algorithms for variable through thickness residual stress evaluation”,

5th European Conference on Residual Stresses – Delft, 28-30 September 1999

M Beghini, L Bertini, L F Mori and W Rosellini, “Genetic algorithm optimization of the hole-drilling method for

nonuniform residual stress fields”, accepted for publication, DOI: 10.1243/03093247JSA457

E.Valentini, A.Benincasa, “Calcolo ottimizzato di tensioni residue con foro eccentrico”, AIAS—XXXVII CONVEGNO

NAZIONALE, 10-13 SETTEMBRE 2008


References

Contact us

Via delle Calandre, 63 - 50041 Calenzano (FI) ITALY

Tel: +39.055.8826302

Fax: +39.055.8826303

www.sintechnology.com

Recognitions

SINT Technology’s test laboratory is accredited to standard ISO/IEC

17025:2005 by the Italian accreditation body ACCREDIA with

certificate no. 0910

Certification of conformity to the requirements of standard

UNI EN ISO 9001

Documents

Eval 7 - Residual Stress Measurement · Eval 7: residual stresses calculation by the hole-drilling method Several theoretical models have been developed by many research centers in