The SORPAS Concept

SORPAS is professional finite element analysis software dedicated for simulation and optimization of resistance welding, mechanical joining and related processes. The integration of engineering expertise with numerical modeling techniques has made SORPAS a unique and powerful tool directly for industrial applications.

Our mission is to make a capable tool that can be easily used by engineers to solve their welding and joining problems in industry. The core values of the SORPAS concept are in the following:

  • Understanding the real problems that the industry are facing
  • Admiring the thoughts of engineers and their way of working
  • Integrating new technology into daily work of engineers in industry

SORPAS can be quickly learned and easily used by engineers in industry. No prior knowledge of numerical simulation is needed.

The integration of engineering expertise with numerical modeling techniques.

The Advantages of SORPAS – Quick and Robust

  • Accuracy           – tested and verified with numerous cases
  • Stability             – smoothly complete nearly all simulations
  • Productivity      – batch simulations and optimizations with Excel input
  • Easy-to-use       – software designed for engineers by engineers
  • Connectivity     – import and export data with other software

The Strengths of SORPAS – Engineered for Industry

  • Expertise in welding and joining
  • Knowledge in materials
  • Experiences in industrial applications
  • Collaborations with innovative partners
  • Numerical modeling techniques

Ensure before weldingTM


Finding the Process Window of good parameters is the key to weld planning, process control and production maintenance for the best weld quality.


Process Optimization and Excel Batch Planning are the mostly used functions of SORPAS to predict the process window for improving weld quality, increasing production stability, and reducing expulsion (splash, spatter).

optimisation of welding parameters for the best weld quality
The software system of SORPAS

The SORPAS system  –  focus on Welding and Joining


The Benefits  –   Ensure before welding

  • Save time
  • Reduce costs
  • Improve weld quality
  • Increase production stability – Reduce expulsion (splash)
  • Technology innovation

SORPAS® can be obtained in two types of license:

  • Special license – with a special upfront license price for the first year and then a lower license fee from the second year.
  • Leased license – with leased license fee for a period of specified number of months or a full year.

One license means one installation of the software on one computer.

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.

SORPAS edition information
  • 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.