Release Notes of HertzWin

Below you will find the history of the HertzWin release notes.

Release 3.4.1 (January 2023)

  • Fixed: bug with (partly) disappearing labels in the graphs led to showing incorrect values;
  • Fixed: bug with zero Normal Force;
  • Fixed: bug in showing material properties from the dropdown list;
  • Fixed: minor translation issue.


Release 3.4.0 (October 2022)

  • New: tangential load (full slip) calculation for elliptical contact;
  • New: indication of slip direction in case of tangential force;
  • New: possibility to show the results for body 1 or for body 2 only;
  • New: switching between line plot along Z-axis (X=Y=0) and a contour plot;
  • New: a left mouse click in the contour plot shows the location and the stress;
  • Improved: great speed improvements for elliptical contact in most cases. Carlson integral RD as described by J.A. Greenwood is used;
  • Updated: help function;
  • Updated: in cases with tangential load, the tensile stress (at the edge of the contact) is now presented for both bodies, instead of the one for ‘body 1’;
  • Correction: tooltip for tensile stress;
  • Fixed: error in the lowest von Mises stress and the principal shear stress values (near zero values  outside the contact area) for circular contact in the contour plot. Maximum values are not affected;
  • Fixed: erroneous center value of the color map for contour plots in certain cases;
  • Fixed: empty material list after adding a new material;
  • Fixed: email address;
  • Fixed: minor glitch in first time startup.

Release 3.3.2 (August 2022)

  • Fixed: bug during program startup with a too high surface roughness.
  • Fixed: bug in contour plot (tangential load) for circular contact. Plot data for Syy and Szz were switched.
  • Improved: some additional error handling.

Release 3.3.1 (March 2022)

  • Improved: ‘wrong’ user input and red colored input fields;
  • Improved: some of the error logging;
  • Improved: help function text in ‘Checks/warnings’;
  • Added: button for showing the release notes;
  • Fixed: some bugs in the ‘wrong’ user input and red colored input fields;
  • Fixed: wrong warning for too high surface roughness in line contact;
  • Fixed: bug with ‘division by zero’.

Release 3.3.0 (April 2021)

  • New: Orthogonal shear stress Tzx, Tzy for free rolling fatigue;
  • Improved: smoother graph ‘force – approach’;
  • Updated: help function;
  • Solved: line contact with zero length causing error notification.

Release 3.2.1 (December 2020)

  • Improved: much faster drawing speed of contour plot;
  • Fixed: contour plot on pc’s with comma as decimal separator showed just one color;
  • Fixed: wrong stress value in the upper label of the color scale legend for Sxx stress in contour plot.

Release 3.2.0 (December 2020)

  • New: influence of a tangential load. The previously used approach is no longer used. Instead, the material stresses below the surface are calculated;
  • New: contour plot of the material stresses with tangential load (also with a tangential load of ‘zero’);
  • Improved: calculation of surface roughness influence. An improved version of the effective contact width curve-fit is now used. This leads to slightly different, but more accurate results of the half width a, b, the shear stress and the von Mises stress;
  • Improved: Help function. Updated and new content added;
  • Repaired: Force vs. impression graph in line contact;
  • Repaired: energy calculation in line contact;
  • Fixed: calculation of the depth of the maximum shear stress and the von Mises at extreme values of the Poisson ratio (> 0.4 or <0.1).

Release 3.1.3 (November 2020)

  • Solved: bug causing serious calculation errors. Update absolutely required!
  • Solved: wrong results after starting HertzWin with roughness values Ra1 and/or Ra2;
  • Solved: erroneous results due to fast typing. It could result in visible recalculations;
  • Improved: calculation speed.

Release 3.1.2 (October 2020)

  • Changed: in line stiffness and impression, now equation [5.58] in K.L. Johnsons book is used if one cylinder radius is infinite;
  • Solved: bug in line contact stiffness combined with surface roughness;
  • Fixed: copyright symbol for some regional settings;
  • Fixed: occasional errors in presenting shear stress and von Mises stress;
  • Improved: calculation of the minimum hardness (although still for indication only);
  • Removed: Traction (tangential load). This is done due to some bugs. The possibility to calculate the effect of tangential loads will be completely updated in future releases.

Release 3.1.1 (May 2020)

  • Solved: bug in material list on certain regional settings;
  • Solved: bug with only a minus sign in the radius entry field;
  • Improved: material fields are now empty after opening the materials list for editing.

Release 3.1.0 (April 2020)

  • Solved: bug in the display of the maximum shear stress of body 1 (shear stress of body 2 was always correct). Error was present since release 2.9.0 and could reach ~1%;
  • Solved: V-spike in Graphs window on some very exceptional combinations of radii in elliptical contact;
  • Added: energy output to clipboard;
  • Improved: some extra robustness in loading older material list;
  • Improved: a language switching issue.

Release 3.0.1 (April 2020)

  • Solved: activation of default settings (new users).

Release 3.0.0 (April 2020)

  • Solved: calculation error in line contact with positive radii. Bug appeared in release 2.10.0 and resulted in a too small contact area and thus higher calculated stresses;
  • Solved: Errors due to ‘prolonged pressing’ of keyboard key. Many code changes;
  • Improved: Warning system less strict, better warning text;
  • Added: Check on angle between the two bodies in elliptical contact;
  • Added: Context sensitive help in the main window;
  • Added: Help function in ‘Graphs’, ‘Material editing’ and pop-up warnings;
  • Minor improvements in the user interface.

Release 2.10.0 (March 2020)

  • New: Calculation of the elastic energy (elastic contact as a spring). User-request;
  • New: Graph of the ‘Force – Impression‘ relation (Graphs window);
  • New: Graph window can be set ‘on top’;
  • New: Possibility to save exported data (Graph window) to any valid folder. The folder is remembered;
  • New: Checks and warnings on radius with respect to radii of the contacting bodies;
  • New: Checks and warnings on impression and stiffness in line contact;
  • New: Check and warning on maximum allowable stress;
  • Improved: Separate material properties for SI and for Imperial units;
  • Updated: No more overwriting of exported data files in the Graph window;
  • Updated: Graph window is conveniently positioned below or besides the main window;
  • Updated: Traction is now disabled if the ‘Graphs’ window is open;
  • Updated: Translation error. Solid lubrication –> Full-Film Lubrication;
  • Updated: Help function with information on Energy calculation, editing the Materials List, the Warning System and a background article;
  • Fixed: Rare bug that could lead to a crash;
  • Fixed: Bug in positioning a text label in the Graphs-window;
  • Fixed: some minor user interface bugs;
  • Fixed: Minor bug in selecting material in de drop-down boxes.

Release 2.9.0 (January 2019)

  • Added: indication of the orientation of the contact ellipse, i.e. is radius A in the X-direction or in the Y-direction or is the contact circular?
  • Changed: In the ‘Graphs-window’, the contact radius a and b are used (instead of using X and Y);
  • Improved: more accurate result in the main Window of Von Mises stresses and maximum shear stress by using numerical optimization (instead of a general curve-fit);
  • Improved: High DPI-scaling under Windows 10;
  • Improved: Scaling in graphs for Von Mises and Tresca if a material with a low Poisson’s ratio is used;
  • Solved: bug with negative radius and angle between axes in certain cases;
  • Updated: hyperlink that directed to the homepage;
  • Removed: limits for the D1 and D2 distances in line contact stiffness (the model is valid for bigger distances than the radii);
  • Fixed: minor bug in the positioning of the ‘infinite checkbox’ for Radius R2x.

Release 2.8.0 (August 2018)

  • New: clicking in graph will show the value for the clicked location;
  • Improved: nicer scaling of grid lines in graphs;
  • Improved: visual indication for cases where the surface roughness is outside the used model;
  • Improved: Dutch/English translation;
  • Improved: some layout issues in ‘Graphs’;
  • Changed: in Line Contact, the limit for D1 and D2 is increased to 1.5x the radius;
  • Added: visual indication in line contact when D1 and/or D2 is too big;
  • Solved: minor bug while starting up in certain situations.

Release 2.7.0 (June 2018)

  • Solved: bug in elliptical contacts under e.g. 90 degrees and big differences in radii;
  • Improved: calculation speed;
  • Added: visual feedback during time consuming calculations;
  • Solved: calculation bug in ‘Graphs’, deflection with circular contacts;
  • Solved: minor calculation error in shear stress and von Mises in cases with traction;
  • Solved: division by zero in certain cases;
  • Removed: traction stiffness (elliptical contacts), it was for uniform tangential displacements only;
  • Corrected: formula in help function ‘Tracebility’ for line impression and stiffness: 5.58 –> 5.57.

Release 2.6.4 (February 2017)

  • Fixed: minor bug in switching units (from MPa to GPa);
  • Updated: more consistant number of significant digits in the results.

Release 2.6.3 (December 2016)

  • New: Average contact stress. It is shown as a yellow tooltip if the mouse cursor hovers above the maximum Hertz contact stress;
  • Solved: minor bugs with comma as decimal separator;
  • Updated: Help function with explanation of the ‘angle’ in elliptical contacts.

Release 2.6.2 (November 2016)

  • Solved: bug in error-checking in line contacts causing an error with negative radius;
  • Updated: some tooltip texts and translations.

Release 2.6.1 (October 2016)

  • Changed: contact stiffness with line contact;
  • Updated: Help function with line contact and local contact stiffness of elliptical contacts;
  • Solved: spurious bug when switching to/from Imperial units;
  • Solved: bug with XY-coordinates in graphs with line contacts;
  • Fixed: position of some unit-labels after switching to/from Imperial units;
  • Minor textual improvements.

Release 2.6.0 (April 2015)

  • Solved: bug in calculation (under certain conditions) with imperial units;
  • Updated: help-function.

Release 2.5.0 (February 2015)

  • New: Imperial units;
  • New: New layout in material editing window
  • Improved: Graphs button does not disappear anymore when the traction force is > 0;
  • Improved: Dashed line in Graphs starts now with a dash;
  • Improved: Units in stress and deflection graphs;
  • Added: maximum shear stress values and depth in Graphs;
  • Fixed: issue with roughness in line contact and negative radius;
  • Fixed: material list, edited by user, is not overwritten when upgrading;
  • Fixed: issue with wrapped text in some labels;
  • Fixed: text label for depth where von Mises stress occurs;
  • Fixed: issue with Tresca and von Mises labels in Graphs;
  • Fixed: issue with changing language if ‘material editing window’ is open;
  • Fixed: stopping HertzWin will now also close the ‘material editing window’ if it is open;
  • Fixed: Bug with stress unit. Switching to kPa did not occur;
  • Fixed: Issue with red background color of results when roughness values are too high;
  • Fixed: check on the maximum value of the Poisson ratio;
  • Fixed: Some minor bugs.

Release 2.4.0 (April 2014)

  • New functionality: Graphs of stresses and displacements;
  • New functionality: Maximum Von Mises stress per contacting body;
  • Depth where the maximum Von Mises stress occurs;
  • Shear stress per contacting body;
  • The Tresca yield stress is now shown as a pop-up if the cursor hovers above the shear stress result;
  • Tables with the used formulas in HertzWin (traceability) have been added to the help function in order to give users the opportunity to check the results of HertzWin.

Release 2.3.1 (December 2013)

  • New functionality: traction stiffness for elliptical contacts;
  • Removed old Windows 98 artifacts in the design;
  • Solved a start-up bug that occurred after exiting in minimized state;
  • Solved a minor calculation-bug that appeared in 2.3.0.

Release 2.3.0 (September 2013)

  • Improved calculation speed in order to avoid erroneous results.

Release 2.2.1 (May 2013)

  • Solved an issue with popup notifications.

Release 2.2.0 (March 2013)

  • Solved a bug that occurred in some cases when switching to elliptical contact. This bug could cause small errors as well.
  • Minor changes to the help function: surface roughness and allowable stress.
  • Added an indication of the validity of the surface roughness model. When the results fall outside the scope of the model, the results turn into red.
  • Limited the input of surface roughness for line contact with a negative radius.

Release 2.1.0 (December 2012)

  • Solved a bug in line contact which resulted in a contact width of zero.
  • Improved layout of program window for monitors having high resolutions.

Release 2.0 (July 2012)

New features and bug-fixes:

  • Calculate the influence of surface roughness.
  • Calculate the minimum required hardness for lifetime.
  • Calculate the influence of traction force.
  • Improved layout of program window for different monitor resolutions.
  • Solved a small bug in the translation setting.
  • Re-arranged the layout.
  • Window position is remembered when exiting.

Release 1.2.2 (May 2012)

  • Added pictures for the shape of the contact area and a picture that explains the meaning of the ‘angle’ parameter.
  • Improved layout for monitors with high resolutions.

Release 1.2.1 (October 2010)

  • Improved rendering for Windows 7

Release 1.2 (July 2009)

  • Solved a bug for the situation with two perpendicular cylinders of equal diameter.

Release 1.1 (April 2009)

  • Added English translation

Release 1.0 (March 2009)

  • First release