Frequently Asked Questions

1. When I run CableCAD I receive an error "E0209 - Security key not found" and the program does not start.  Why can't the program start?
   
   First, make sure that the security key is securely connected to your computer's parallel printer port.  If the key is securely connected and you still get this error then you may need to reinstall the system driver for the security key.  This system driver is installed as part of the CableCAD setup.  To reinstall the system driver you can either uninstall CableCAD and reinstall it from the CableCAD CD or you can follow the instructions in the CableCAD readme.txt file for manually installing the system driver.  To uninstall CableCAD use the "Add/Remove Program" utility in the Windows Control Panel.
   
   
2. I've heard of Finite Element Analysis, but what is Layer Element Analysis?
   
   With the Layer Element Modeler (LEM), the cable is represented as individual layer "elements" that interact structurally with adjacent layer elements.  The LEM assumes geometrical and load symmetry about the cable axis.  Thus, cable layers must be either a circular cylinder or filled with identical, equally-spaced wires.  Any combination of cylindrical and helical wire layers can be assembled into a model.
   
   With the Finite Element Modeler (FEM), geometrical and load asymmetry can be handled.  Also, the FEM provides more accurate and detailed stress and deformation results.
   
   
3. What kind of elements are used in a finite element model?
   
   All circular components such as round wires, jacketed round wires and cylinders are modeled with circular ring finite elements developed specifically for CableCAD.
   
   The ring elements are based on a Fourier series shape function.  The ring elements within a single circular component are joined and a stiffness matrix is assembled.  All internal nodal degrees-of-freedom are then condensed to degrees-of-freedom acting only at the contact points between adjacent components.  The assembly of the contact-point degrees-of-freedom form the finite element model.  Two degrees-of-freedom, one radial and one circumferential translation are solved at each of the contact points.
   
   These elements are capable of showing detailed stress contours including the stress concentrations occurring in components at contact points.
   
   
4. What are the .def, .dis, .efs, .mod, .plt and .txt files that are created in the DATA folder?  Do I need to keep all of these files?
   
   The only file that needs to be archived is the .mod file.  This file contains the all the physical definition and load data in your model.  All of the other files are solution output files.  You could archive the output files with the model file, but it is not recommended since most problems only take a few minutes or less of solution time.  Thus the output files can be quickly recreated from an archived model file.
   
   The .txt file contains the results that you see when you issue the "List Output File" command.  It is an ASCII text formatted file.
   
   The .plt file is used to generate graphs and contour plots.
   
   The last three file types are only created from a Finite Element Analysis:
   
   
1. The .def file is used to generate deformation plots.
2. The .dis file is the nodal displacement list file.  It is an ASCII text formatted file.
3. The .efs file contains the effective stress results.