NeXel
models and results in Excel

NeXel is the new NextFEM product for working with your Excel tables and Designer models!
With the convenient multifuction bar and engine to manage data and results, NeXel is an unfailing companion for those who use Excel for structural checks!

 

The add-on for Excel also provides unit conversion directly into formulas.

It automates all the operations you’re now performing manually!

Current version: 1.3 –  1st July 2023 – Requires NextFEM Designer v2.2.0.0 or later

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Basic usage of NeXel

NeXel operates directly at the Excel formula level, allowing models to be handled natively within Excel.

For example, let’s open the provided beam_continue.xlsx file from the installation folder. All operations from the buttons generate entry in the current cell of a formula, so it is necessary to place on an empty cell before giving a command.

 

Commands in Model group

Cell B2 presents the result of opening the model, which you can set from the “Open model” button. The formula that reads is =NF.openModel(“beam_continue.nxf”), that is, the loading of the beam_continue.nxf model contained in the same folder is requested. Generally, you can use complete paths as the command argument, with the exception of files contained in the same folder as the Excel file you are working with, which allows to use only the filename in the path.

By the drop-down menu, the following commands are available.

– The Open Model command opens the selected model in the mask that appears;
– the New model command resets the open model;
– the Write functions option enables the writing of the model opening and saving functions in the current cell (e.g. in the beam_continue file see cell B2). It is recommended to enable this option only for special needs of automation of operations. By default the option is disabled.

The Save model button allows saving the open model, while Save model as… allows saving under another name.

The View model button allows the current model to be opened in NextFEM Designer. Any changes or recalculations are reflected on the cells only after saving the model and pressing Refresh. The button Reload model allows to reload the currently opened model (see Tools section).

The Load functions button is generally not necessary – in fact, it allows NeXel functions to be loaded temporarily, only for the current session. Model name returns the model name (coincident with the file name).

The Convert units command is a powerful provider for converting units. For example, the formula =NF.convertUnit(H8; “kN*m”; “kgf*cm”) allows you to convert the value in cell H8 from kN*m to kgf*m. In case of an error it returns 0. Force unit returns the unit of measure of force, while Lenght unit returns the unit of measure of length

Data group

The commands in the “Data” group are briefly described below:

  • Nodes returns the list of nodes in the model, by column
  • Node position returns the coordinates of the desired node
  • Elements returns the list of elements in the model, by column
  • Element size returns the characteristic length of the element (length for beams, area for shells, volume for solids)
  • Load cases returns the defined base load cases of the model
  • Load combinations returns all the defined combinations in the model, including envelopes
  • Add combinations returns all combinations of type “Linear add” defined in the model
  • Loads table return the loads table as defined in the model
  • Modify loads change the selected rows in the load table
  • Get groups lists the groups present in the model, by column
  • Get sections lists the sections defined in the model, in 2 columns (ID, name)
  • Get sections props returns all section properties
  • Get Functions lists the functions defined in the model, in 3 columns (ID, name, ordered units)
  • Get Function series reports the series contained in the selected function by ID, in 2 columns (abscissa and ordinate)
  • Get Function data reports the general data of the series (e.g. for a spectrum: ag, soil type, etc.)

Results group

For the “Results” command group:

  • Results avail. returns Boolean value indicating whether or not results are present in the loaded model. If not, all the following functions return 0
  • Nodal displ. returns the displacement for the node and the desired degree of freedom (DoF)
  • Node reactions returns the nodal reaction for the constrained node and the desired DoF
  • Beam forces returns the selected stress value at the specified station (1 to 5) for a beam
  • Beam diagrams returns the stress diagram for a beam for the desired LoG, at 21 default points
  • Section cut forces returns the specified stress for an existing section cut, enumerated by the Get groups command
  • Shell Wood-Armer moments returns the maximum or minimum moments (specify in the “type” argument, 1 to 4) for the moments at Wood-Armer in the shells. The groupName argument is the name of the group to which the shells belong.

Tools group

Commands in this group do not return results to the selected cell, but open other utilities included in NextFEM Designer to add sections or design functions, which can be called back into the sheet using commands in the Data group. Once these tools are closed, the model must be reloaded into Excel with the Reload model command.

  • Section Analyzer starts the calculation mask of the sections defined in the model, allowing, if the license is active, also the resistant calculation of sections in reinforced concrete, steel, wood, aluminum, thin-walled, etc.
  • EC8 Spectrum adds to the current model the design spectrum according to Eurocode 8
  • NTC Spectrum adds to the current model the design spectrum according to NTC2018
  • NTC Wind adds wind load function according to NTC2018 to the current model
  • NTC Snow adds to the current model the snow load function according to NTC2018
  • EC1 Wind adds wind load function according to NTC2018 to the current model
  • EC1 Snow adds wind load function according to NTC2018 to the current model
  • Sine function adds a sinusoidal function to the current model according to the given parameters.

Live Link is the new technology for real-time transport of model data and results to and from NextFEM Designer. Open NextFEM Designer and upload the model. You need to activate the REST API Server plugin in NextFEM Designer, then in NeXel press on the Live Link button to be able to access real-time features of the opened model (including results) with the same commands of NeXel.


Enjoy your work with NeXel!