Non-destructive test methods, to a greater and lesser degree, often require calculations to be performed. These calculations may be used in a variety of ways;
• to establish techniques
• to establish physical limitations
• to estimate locations
• to derive various parameters about the test piece or testing equipment.

The Problem Solver series of software, developed by E. Ginzel and R. Ginzel, allows you to calculate many of the common and some of the not so common parameters encountered in the various methods of NDT.

GENERAL DESCRIPTION.

This programme is designed to be a very user friendly package for users of IBM compatible computers. Easy to follow menus can be keyboard or mouse driven. Function keys have been programmed to simplify and speed up many steps.

Many of the topics have useful background information available when the "Help Menu" is called on. Units used are commonly used metric units. lf you are not comfortable using metric units, a metric conversion utility it provided.

User comments and suggestions are welcome. Please address your suggestions to:

Ed Ginzel,
368 Lexington Road,
Waterloo,
Ontario, Canada. N2K 2K2

GETTING STARTED

Hard Disk Installation

Unzip the Problem solver in a directory of your choice. For example UTPS.
It is important to use for RT, ECT Problem solver other directory names.
In order that the Problem Solver will utilize your mouse, the mouse driver for your system must be active. lf you want your menus to be rnouse driven, first activate your mouse using the applicable command. Problem Solver Software (PSS) defaults to "no mouse available" otherwise. (Note: this assumes your mouse is on your path.)

To execute PSS, open the appropriate executable file, eg. utps.exe for the Ultrasonic Problem Solver, from your Windows File Manager.

Following the introduction is the main menu. First time users should move to Item 7 - Setup.

The highlighted bar can be moved using the up or down arrows, or the mouse if installed.

Press "Enter", or click if mouse installed, to execute the item selected by the highlighted bar, in this case #7 - Setup. Then answer the question "yes" or "no" to make any changes. "No" returns you to the main menu. lf "yes" was selected, you would then choose whether or not to use a mouse, and select the type of monitor you are using; either colour or monochrom.

You are now ready to use the Problem Solver Software.

FUNCTION KEYS

To facilitate a number of operations several function keys have been assigned specific duties. These funtions are as follows:

Fl - Help
F2 - Edit Help
F3 - View Medium Table
F4 - View Transducer Material Table
F5 - Send Data to Printer
F6 - Formfeed to Printer
F7 - Linefeed to Printer
F8 - Main Menu
F9 - Function Menu
F10 - Exit to DOS or WINDOWS

In addition to the function keys, pressing the ESC key returns you to the previous menu.

MAIN MENU ITEMS

The Main Menu is composed of 7 items.
ITEM 7 SETUP, has already been discussed. lt is used to select monitor type and availability of a mouse.

The working portion of the programme is contained in items 1 through 6.

ITEM 1 TABLES

Two tables are provided:
a) A materials table
b) A transducer material table

a) The Material Table.
This table is a handy reference giving you a list of materials commonly encountered in ultrasonic testing, their longitudinal and transverse acoustic velocities, density and normal state of matter. You may add 5 new materials to this list and delete them as you find necessary.

b) The Transducer Materials Table.
This is a table of commonly used piezoelectric materials used in ultrasonic testing. Values quoted are approximate since considerable variations may occur from manufacturer to manufacturer. You may add new materials to this list and delete them as you find necessary.

These tables can be used to obtain values in many of the equations solved by this software. The Tables can be printed or can be referred to while working with the Problem Solver.

ITEM 2 PROBE PARAMETER CHARACTERISTICS

This item allows you to calculate the 1) Near Zone, and 2) Q factor of a transducer.

Calculation of the near zone is made for flat disc shaped crystals.

Q factor is the quality of a system's mechanical resonance. In order to obtain this, we must have information about the material being vibrated (the piezoelectric crystal) and the material on either side of it (backing and couplant or the test piece.) A high value for Q indicates a relatively high amplitude vibration with relatively low frequency bandwidth. Low Q values imply loweramplitude vibration and broader frequency bandwidths.

ITEM 3 WAVE CHARACTERISTICS OF ULTRASONICS

This item deals with acoustic impedance, wavelengths and time of flight.

1) Acoustic Impedance
For acoustic impedance you may choose to view the acoustic impedances in the materials table or find a specific acoustic impedance for a material not listed in the table.

2) Wavelength Determination
For the wavelength of ultrasound you must specify a frequency. Selecting to view the wavelength of materials in the table you will be asked to enter a frequency in the highlighted bar at the top of the page. Entering a new frequency changes all the values in the table. (Note: entering "0" results in no change.) You may choose to determine the wavelength in a material not listed in the table. In the customized wavelength portion of this item, you will enter the test frequency and velocity of sound in the new medium, and the correct wavelength will be shown.

3) Time of Flight
This option allows you to calculate the time or distance traversed by sound in a specified medium. The results for both through transmission and pulse - echo techniques are calculated simultaneously.

ITEM 4 GEOMETRIC - OPTICAL TREATMENT OF ULTRASOUND.

As with light, sound travel is often illustrated by use of rays to indicate beam direction (hence "geometric - optical" treatment.) This item allows you to calculate distances and angles usually illustrated with ray representations.

1) Snell's Law
This allows you to calculate any refracted angle and indicates to you if your incident angle is too steep to result in a refracted angle.

2) Geometry Calculations
Determination of standoff (distance from sound entry point to surface point at flaw) and depth of the indication from the surface are two most common factors desired in flaw location using ultrasonics. You are given the option to calculate these parameters for both flat and curved surfaces.

3) Angle of Divergence
Divergence of sound off flat surfaced probes is a result of the wave nature of sound; however, since this divergence can be shown using rays, it is calculated in this item. Both disc and rectangular shaped probes can be entered and both 6dB and 20dB beam spreads can be calculated.

4) Convergence Point
The point of convergence applies to focussed transducers. Focussed probes are given a focal distance in water; if another couplant is used or if a test piece is placed at some point in the sound beam within the focal distance, the point of focus, as measured from the probe face, willchange.

ITEM 5 MODULII, REFLECTION AND TRANSMISSION COEFFICIENTS.

1) Modulii
Young's Modulus, the modulus of Shear and Poisson's Ratio, are useful engineering quantities that can be calculated from ultrasonic information.

In addition to custom calculations of these values for specific properties of any material, these values are tabulated for the materials in the materials table.

2) R and D (Reflection & Transmission Coefficients)
The coefficients of reflection and transmission can be calculated for four different boundary conditions. This can be useful to determine the relative energy available for flaw detection after a boundary has been crossed or reflected from.

ITEM 6 UTILITIES.

In addition to DOS command and a quick look at your disk directory, this utility allows you to make conversions in 3 useful areas:

a) Metric conversions
b) Trigonometric conversions
c) dB ratios


a) Metric conversions.
lf you are more accustomed to using imperial units, this utility will allow you to enter your imperial unit and display its equivalent metric unit.
Conversely, a metric unit entered will display its Imperial equivalent.

b) Trigonometric conversions.
This utility converts radians to degrees and degrees to radians. In addition to radian conversion, the three common trigonometric functions (sine, cosine and tangent) can be displayed for any degree entered.

c) dB ratios
dB ratio conversions allow you to calculate change in signal height as a percentage of the original signal height with a specified dB increment (up or down). Conversely, signal height changes can be converted to an equivalent dB change.

Standard values and equations have been used for all solutions. Sources for these include:

Ultrasonic Testing of Materials, J. & H. Krautkraemer,
Springer-Verlag, Berlin, 1983.
Engineering Formulas 5th edition, K. Gieck,
McGraw-Hill, 1986.
Condensed Reference Series for Ultrasonic NDT,
Automation lndustries, Inc.
Conversion Factors, C.J. Pennycuick,
University of Chicago Press, 1987
Non-Destructive Testing Views, Reviews and Previews,
A. Reid, Oxford University Press, 1969.


In addition to the above sources, the following have made significant contributions: Dr. M Dolby, E. Ginzel, R. Ginzel and R. Rumpler.

APPENDIX A