Release Notes of HertzWin

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

Release 3.5.0 (April 2023)

  • Improved: cross hair when clicking in the contour or line plot;
  • Improved: speed when switching back and forth between contour plots;
  • Fixed: labeling error in contour plot;
  • Fixed: the width of the contour plot;
  • Fixed: scaling in the dZ line plot;
  • Fixed: legend in line plot (line color and type);
  • Fixed: missing grid line in line plot.

Release 3.4.1 (January 2023)

  • Fixed: bug with (partially) disappearing labels in the graphs caused to show wrong values;
  • Fixed: bug with zero normal force;
  • Fixed: bug with displaying material properties from the drop-down list;
  • Fixed: minor translation problem.

Release 3.4.0 (October 2022)

  • New: tangential load (full slip) calculation for elliptical contact;
  • New: indication for slip direction in case of tangential force;
  • New: possibility to show the results for body 1 or for body 2 only;
  • New: toggle between line plot along Z axis (X=Y=0) and contour plot;
  • New: a left mouse click in the contour plot shows the location and the stress;
  • Improved: major speed improvements for elliptical contact in most cases. Use of the Carlson integral RD as described by J.A. Greenwood;
  • Updated: help function;
  • Updated: in cases with tangential loading, the tensile stress (at the edge of the contact) is now displayed 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 unaffected;
  • Fixed: incorrect color map center value for contour plots in certain certain cases;
  • Fixed: empty material list after adding a new material;
  • Fixed: email address;
  • Fixed: minor bug on first start.

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 have been swapped;
  • 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 to show 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 force-impression plot;
  • Updated: help function;
  • Solved: line contact with zero length causing error message.

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 only 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: tangential load influence. The previously approximation is no longer used. Instead the subsurface stresses are calculated;
  • New: contour plot of the sub-surface stresses with a tangential load even with a tangential load of ‘zero’);
  • Improved: calculation of roughness effects. An improved version of the effective radius fit is now used. This lead to slightly different, but more accurate results for the semi-width b, the shear stress and the von Mises stress;
  • Improved: Help function. Updated and added new content;
  • Repaired: Graph showing force versus displacement in line contact;
  • Repaired: Energy calculation in line contact;
  • Fixed: calculation the of depth of the maximum shear stress and the von Mises for extreme values of the Poisson ratio (>0.4 or <0.1).

Release 3.1.3 (November 2020)

  • Solved: bug that caused serious calculation errors. Update absolutely necessary!
  • Solved: wrong results after starting HertzWin with roughness values Ra1 and/or Ra2;
  • Solved: wrong results due to fast typing. Will result in visible recalculations;
  • Improved: calculation speed.

Release 3.1.2 (October 2020)

  • Changed: in line stiffness and impression, equation [5.58] in K.L. Johnson’s book is used when one cylinder radius is infinite;
  • Fixed: bug in line contact stiffness with surface roughness;
  • Fixed: copyright symbol for some regional settings;
  • Fixed: occasional errors in displaying shear stress and von Mises stress;
  • Improved: calculation of the minimum hardness (but still only for indication);
  • Removed: Traction (tangential load). This is done due to some bugs. The ability 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 input field;
  • Improved: material fields are now empty after opening the material list for editing.

Release 3.1.0 (April 2020)

  • Solved: error in shear stress of body 1. Error was ~1% max. Present since release 2.9.0;
  • Solved: very rare bug in ‘Graphs’: spike in shear stress graph for exceptional/unusual combination of radii;
  • Added: energy output to clipboard;
  • Improved: some additional robustness when loading older material list;
  • Improved: a language switching problem.

Release 3.0.1 (April 2020)

  • Solved: enable default settings (for new users).

Release 3.0.0 (April 2020)

  • Solved: calculation error in line contact. Bug appeared in release 2.10.0 and resulted in too small contact area and thus higher stresses;
  • Solved: errors due to ‘prolonged pressing of keyboard key. Many code changes;
  • Improved: warning system less strict, better warning text;
  • Added: check for angle between the two bodies in elliptical contact;
  • Updated: help function for pop-up warnings;
  • Updated: context-sensitive help in ‘Graphs’, ‘Material Editing’ and pop-up warnings;
  • Minor user interface improvements.

Release 2.10.0 (March 2020)

  • New: elastic energy calculation (elastic contact as a spring, user request);
  • New: graph of the ‘Force-Impression’ relation (Graph window);
  • New: graph window can be set to ‘on top’;
  • New: possibility to save exported data (Graph window) in any valid folder. The folder will remembered;
  • New: checks and warnings on radius with respect to the radii of the contacting bodies;
  • New: checks and warnings for impression and stiffness in line contact;
  • New: checks and warnings for maximum allowable stress;
  • Improved: separate material properties for SI and for Imperial units;
  • Updated: exported data files are no longer overwritten in the Graph window;
  • Updated: graph window is conveniently positioned below or next to the main window;
  • Updated: traction is now disabled when the ‘Graphs’ window is open;
  • Updated: translation error. Solid Lubrication –> Full Film Lubrication;
  • Updated: help function with information about Energy calculation, editing the Materials List, the Warning System and a background article;
  • Fixed: rare bug that could cause the program to crash;
  • Fixed: bug in positioning a text label in the Graphs-window;
  • Fixed: some minor user interface bugs;
  • Fixed: minor bug in material selection in the drop-down boxes.

Release 2.9.0 (January 2019)

  • Added: indication of the orientation of the contact ellipse, i.e. is the 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 on Windows 10;
  • Improved: Scaling in plots for von Mises and Tresca when a material with a low Poisson’s ratio is used;
  • Solved: bug with negative radius and angle between axes in certain cases;
  • Updated: hyperlink pointing to the home page homepage;
  • Removed: limits for the D1 and D2 distances in line contact stiffness (the model is valid for larger 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 the graph shows 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 now set to 1.5x the radius;
  • Added: visual indication in line contact where D1 > 1.5 x R1x and/or D2 > 1.5 x R2x;
  • Solved: minor startup bug 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 ‘Traceability’ for line impression and stiffness: 5.58 –> 5.57.

Release 2.6.5 (February 2018)

  • Fixed: influence of traction forces (tangential load) on shear stress.

Release 2.6.4 (February 2017)

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

Release 2.6.3 (December 2016)

  • New: average contact stress. It is shown as a yellow tool-tip if the mouse cursor hovers above the maximum Hertz contact stress;
  • Solved: bug 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 tool-tip 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: Sporadic bug when switching to/from Imperial units;
  • Solved: bug with XY-coordinates in graphs 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 with imperial units under certain conditions;
  • Updated: help-function.

Release 2.5.0 (February 2015)

  • New: imperial units;
  • 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;
  • Improved: new layout in material editing window;
  • 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: graphs of subsurface stresses and displacements;
  • New: maximum Von Mises stress per contacting body;
  • New: depth where the maximum Von Mises stress occurs;
  • New: shear stress per contacting body;
  • The Tresca yield stress is now displayed as a popup when the cursor is hovered over the shear stress result;
  • Tables with the formulas used in HertzWin (traceability) have been added to the help function to allow users to check the results of HertzWin.

Release 2.3.1 (December 2013)

  • New: traction stiffness for elliptical contacts;
  • Removed: old Windows 98 artifacts in the design;
  • Solved: a start-up bug that occurred during start-up 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;
  • 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;
  • Minor changes to the help function: surface roughness and allowable stress;
  • 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 0;
  • Improved: layout of program window for monitors having high resolutions.

Release 2.0 (July 2012)

  • Added: calculate the influence of surface roughness;
  • Added: calculate the minimum required hardness for lifetime;
  • Added: calculate the influence of traction force;
  • Improved: layout of program window for different monitor resolutions;
  • Solved: a small bug in the translation setting;
  • Improved: re-arranged the layout;
  • Improved: 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;
  • The images are now included in the executable;
  • Improved: layout for monitors with high resolutions.

Release 1.2.1 (October 2010)

  • Improved rendering for Windows 7

Release 1.2 (July 2009)

  • Fixed: bug for the situation with two perpendicular cylinders of equal diameter.

Release 1.1 (April 2009)

  • Added: English language and help function.

Release 1.0 (March 2009)

  • First release