SORPAS® 2D.welding

sorpas 2d logo

SORPAS® is dedicated professional software for resistance welding simulation and optimization of resistance welding processes. It has been specially developed for engineers by engineers for welding simulations. It doesn’t need any prior knowledge in numerical simulations, but can be easily learned and used by engineers with knowledge of welding and materials. The integration of welding expertise with numerical techniques has made SORPAS® a unique and powerful tool for engineers directly working in industry.

SORPAS 2D interface

“We have been using SORPAS® since 2001 and have made many innovative developments in resistance welding. We are now further extending the applications of simulation to process optimization for supporting production planning.”

– Mr. Matthias Graul, Volkswagen AG, Germany

The build-in material database in SORPAS® has included nearly all commonly used metal materials including all types of steels, aluminum alloys, titanium alloys, copper alloys, nickel based alloys, surface coating materials, pure metals and high melting metals such as tungsten and molybdenum etc. The users can also add their own materials. It is possible to simulate with dimensions of weld parts ranging from ordinary sizes in millimeters down to micro sizes in a fraction of micron with welding machines of all types of power sources including AC, DC, MFDC, inverter, and capacitor discharge.


SORPAS 2D.welding soultion - excel batch simulation

Excel batch planning

SORPAS provides an efficient way of optimizing welding process parameters for many weld points.

SORPAS 2D.welding soultion - intelligent weld planning

Intelligent weld planning

We provide fully automated weld planning function to optimize welding parameters and predict expulsion limit.

SORPAS 2D.welding soultion - process optimization

Process optimization

SORPAS predicts range for your task and makes an overview with weld growth curves and weldability lobes.

Production maintenance

With simulation of the welding process by SORPAS, you can identify problem and improve welding results.

Weldability of materials

SORPAS has been used as a powerful tool to evaluate the weldability of materials both during the research and for production.

Weld quality

To predict weld quality, SORPAS simulates weld nugget formation, micro structures and hardness, and weld strength tests.


  • Save costs
  • Reduce lead time / time to market
  • Speed up production running-in
  • Improve weld quality
  • Increase production stability
  • Facilitate innovation
  • Modernize technology

Numerous new inventions have been supported with SORPAS® simulations



SORPAS® has been applied in various industries for solving problems in spot welding, projection welding, butt welding and micro resistance welding and supporting research and development as well as process parameter optimizations.

SORPAS 2D welding simulation result with real test
  • Evaluating weldability of materials
  • Evaluating design of weld combinations
  • Evaluating design of electrodes
  • Inventing new applications
weldability lobe curves and weld nugget size development
  • Predicting weldability lobes and weld growth curves
  • Optimizing process parameter settings
  • Determining welding and cooling procedures
  • Trouble shooting welding problems

Welding simulation cases

SORPAS simulation of spot welding of 3 sheet

Spot welding:

Simulation of three-sheet spot welding of low carbon steel, high strength low alloy (HSLA) steel and Dual Phase (DP) steel sheets.

SORPAS simulation of 2d square nut welding

Projection welding:

Simulation of projection welding of square nut with corner projections welded to steel sheet showing the weld after collapse of the projections.

SORPAS simulation of resistance butt welding

Butt welding:

Simulation of resistance butt welding of two steel plates welded at the ends with resistance heating and subsequent forging and butt welding.

SORPAS simulation of parallel gap welding

Parallel gap welding:

Simulation of parallel gap welding (micro resistance welding) for joining thin foil to substrate plate of titanium alloys.

Report of simulation

weld planning example from SORPAS

After each simulation, SORPAS® will generate a Report of Simulation for documentation.

Left image is a typical report for a spot welding simulation. In the upper part, it shows the initial welding conditions including material combinations, geometry of electrodes and workpieces as well as the welding process parameter settings. In the lower part, it shows the main simulation results with a selected process parameter curve, the final temperature distribution with the weld nugget dimension in each workpiece.

In order to satisfy various requirements of individual users, three editions of SORPAS® are available as listed in the table below. The Enterprise Edition is with the automated procedures for process parameter optimizations including prediction of the weld growth curves and weldability lobes as well as verification of contact resistance, giving users the ultimate benefits to ensure before welding.

  • Graphic user interface for data input: include the New Input Wizard and the Data file editor for design of geometries and selection of materials (from integrated databases) for electrodes, weld parts and coatings, and settings of welding process parameters.
  • Automatic mesh generation: automatically generate FEM mesh for spot welding and/or according to user defined number of elements and density distributions.
  • Electrical model: calculates the current distribution and heat generation depending on types of weld current and materials of weld combinations.
  • Thermal model (including optional metallurgical model): calculates the heat transfer, temperature development, materials properties changing with temperature, and weld nugget formation.
  • Mechanical model: calculates the mechanical reactions including deformation of materials, evolution of contact areas at interfaces, stress and strain status depending on welding machine characteristics and dynamics.
  • Graphic display of results: display of simulation results including curves of process parameters and animations of the evolution of variable (temperature, current etc.) distribution and development of the weld nugget shape and size in each material.
  • Editor for databases: the user interface for editing (adding, removing and modifying) data in the three integrated databases for material properties, electrode forms and designs of workpieces.
  • Build-in databases: three database are integrated in the software system including the material database with properties of most commonly used standard materials, the electrode database with most standard electrode forms (ISO 5821), and the workpiece database for retrievable design of weld parts.
  • Single simulation: simulation of one specific welding process with specified electrode and material combinations, and given process parameter settings (weld current, force and time etc.).
  • Batch simulation: run a batch of simulations following a list of predefined data files of different welding conditions or procedures for process optimization.
  • Automated verification of contact resistance: automatically verify the contact resistance factors against a tested weld nugget size for verifying the data of new materials.
  • Automated optimization of weld current: two optimization functions are implemented for optimization of the weld current. One is for automatically running a series of simulations according to user-defined range of weld current from a lower limit to a higher limit with a given increment, whereby the weld growth curve will be generated. The other one is for automatically running simulations to seek for the optimal weld current according to a targeted objective diameter of the weld nugget.
  • Automated generation of weldability lobe: two types of the weldability lobes can be generated automatically following the procedures recommended in ISO 14327:2004, where two process parameters are varied. One type is to vary the weld current and time while keep weld force constant. The other type is to vary the weld current and force while keep the weld time constant. The splash limits are predicted and the weld ranges are indicated according to three reference weld nugget diameters (minimum, maximum and nominal) which are given by users.