The following tools are available:
- Free Edge;
- Mass and COG Table;
- Moment Shear Force;
- Thickness Plot;
- Moment Ratio;
- Weld Summation Tool;
- Effective Plate Width;
- Stress Gradient.
- creates a text file with materials, properties, nodes and elements ids without the model data. The file is used to debug user problems without having the customer model.
Free Edge Tool automatically finds free edges between the elements.
To open Free Edge executefrom the main menu.
Pressand the table will be filled with the groups of elements that have Free Edges.
Pressto select all groups from the list and - to deselect;
- display only groups of elements.
- highlight the selected groups of elements.
- export selected groups to Femap;
- export selected groups to components;
Mass and Center of Gravity Table is used to automatically calculate mass and center of gravity characteristics on the user-defined selections.
To add Mass and Center of Gravity executefrom the main menu.
Selection - elements that will be intersected with the selections defined below;
Elements Count - first value is the amount of elements that were found on Selection. Second value is the total amount of elements that exist in the model;
COG X, Y, Z - coordinates of the center of gravity;
Mass - mass of the selection.
Note: Overall row is a Mass of all selections.
Selections can be defined using Selection List Control.
In order to check the validity of a ship Moment Shear Force can be performed.
To add Moment Shear Force executefrom the main menu.
Select loads using Multiple Loads Selector.
Define selection using Selector Control
Force/Moment X/Y/Z - select what Forces and Moments to display in the table.
Coordinate system - present results in the selected coordinate system;
Horizontal Axis - axis along the length of the model;
Model Length - defined automatically = Maximum - Minimum along the Horizontal axis;
Portside Axis - axis along the height of the model (perpendicular to the Horizontal axis);
Step - model Length is divided by steps in a number of the locations where Forces and Moments will be calculated (N = Moment Length / Step).
By default forces and moments are calculated around [0;0;0]. Selection option Redefine Origin and click to select the location on the model. Press to set the origin to average coordinates from selection for all axes and min coordinate for the horizontal axis.
Sum of Forces and Moments are calculated based on Grid Point (Elemental-Nodal ENFO, ENMO) Forces/Moments. Pay attention that the results are included in the analysis.
For Load Group it is possible to show Min/Max/Abs values and also show loads from load group that contains min/max values (Relevant Min/Max).
Pressto display the results.
- select direction and display plot:
Thickness plot is created to display plate elements thicknesses for flat elements selections like frames, decks and longitudinals in Femap.
It displays a nice plot with the properties thicknesses using the text labels. The position of a label is calculated to be on the top of the elements with the same property:
To add Thickness Plot executefrom the main menu.
Flat selections (as frames) are recommended to be used for thickness plots. The selection can be defined in 3 ways:
- select section from the panel finder;
- select a group;
- define any custom selection using Selector Control.
It is required to select the View for the plot. It can be chosen from the list or imported from the Femap active view. To edit the selected view options press .
Font Size can be set from 8pt to 32pt. By default 8pt size is used.
In most cases, the default value of an Angle may not be changed. Only in the case when the selection is quite curved or for a hull, it should be increased. If too many labels are displayed on the area with the elements of the same property, increase the Angle option. For a hull 30 degrees are recommended.
Four types of data can be displayed on the labels: plate thickness; property ID; ID and Title; ID, Title and Thickness:
Press to display a plot.
To add thickness plots for all sections at once executefrom the main menu.
In the Create Multiple Thickness Plots dialog instead of one selection - multiple selections can be defined using Selection List Control. As a result, multiple plots are created:
Moment Ratio calculates Kc and Bm factors (Eurocode3), Cb reduction factor (AISC), Cm - moment ratio on the ends of members found by Beam Member Finder.
It is used in the moment reduction factors calculations in the following standards: API 2A RP (table D.3-1), ISO 19902 (table 13.5-1) and Norsok N004 (table 6-2):
And moment reduction factors according to Eurocode3 (table 6.6):
Cb (Aisc2010) lateral-torsional buckling modification factor for AISC360-10 is calculated for the Moment Ratio Torsional Y and Z:
Cb lateral-torsional buckling modification factor for AISC ASD 89 (Section F1.3) is calculated for Moment Ratio Torsional Y and Z:
Bm Equivalent uniform moment factor for EN 1993-1-2:
Four moment ratio tools are created by default for length y, length z and length torsional members with Y/Z moment ratios. To edit the respective Moment Ratio executefrom the main menu.
M1(end min) and M2(end max) - the bending moment on the ends of the beam member.
M1/M2 - the moment ratio between the ends of the beam member..
Min/Max - the minimum/maximum bending moment over the full member.
Kc - the reduction factor according to Eurocode3, Part 1-1 Table 6.6.
Cb (Aisc89) - the lateral-torsional buckling modification factor according to AISC ASD 89.
Cb (Aisc2010) - the lateral-torsional buckling modification factor according to AISC360-10.
Bm (EC3 Fire Design) - Equivalent uniform moment factor according to Eurocode3, Part 1-2 Figure 4.2.
Select Load using Load Selector Control.
- plot moment ratios (M1/M2) for the selected members;
- plot ids for the selected members;
- plot Cm Type for the selected members. Cm type can be changed in Beam Member Finder:
- plot Kc factor;
- plot Cb factor for AISC ASD 89 or AISC 360-10;
- highlight the selected beam members;
- preview only selected beam members.
For the selected member the bending moment diagram is displayed. End moments, Min/Max over the full member are shown with labels:
Example: Calculation of the reduction moment factors Cm according to ISO 19902:
Weld Summation tool is used to summarize Grid Point Forces that will be used in Weld Checks to calculate the Weld Stresses.
Press to automatically highlight a single selected weld/weld part from the list.
There are two methods available:
- Summarize per weld part - summarize forces at all welded nodes of the respective weld part;
- Summarize per elements (beta) - calculate forces at each welded node of respective weld part element. Force is summed from neighbor elements that contain only one welded node;
Show results only for welded parts - display only welded parts of the welds in the table. The non-welded parts do not provide results in weld checks.
Select Load using Load Selector Control.
Pressto display results.
This method is used for the straight welds. Weld length and a coordinate system are taken from the Weld Finder Tool.
Forces are summarized over the weld nodes (41 - 47) using elements only from the respective weld part (101 - 126).
Weld part origin is used to calculate a moment arm for extra moments from the forces.
After forces are summarized, they are transformed into a weld part coordinate system.
This method calculates forces for each node and related element from a weld part. Besides the weld length and a coordinate system are calculated for each weld node taking into account neighbor weld part elements.
Weld length is a sum of the half of the element's length along the weld direction from both sides of the weld node (L2-L6 on the picture):
Note: If the weld is not closed the weld length for the start and for the end nodes is taken as a full length along the weld direction of the neighbor element (L1 and L7 on the picture).
Elements that are attached with one node to the weld are not taken into account in weld checks. Forces/moments are transferred to the neighbor elements by the portion of their weld length in the calculations:
F1 = F * (a / (a+b)); F2 = F * (b / (a+b));
Note: For non-welded nodes, the result is taken by the following rule:
- For Element 1: FN1 = Average (FN4, FN5)
- For Element 2: Forces are transferred to Element 1 and Element 3, consequently result is 0;
- For Element 3: FN3 = FN6; FN2 = FN5
- open Weld Finder Tool to recognize welds;
Pressto recalculate forces. All results in weld checks will be cleared automatically after confirmation
- highlight selected weld parts;
- preview selected weld parts;
- display criteria plot for selected direction:
Note: Force and moments for the elemental method will show the absolute maximum value on the element from among its welded nodes.
- display colored weld plot with weld ids as labels;
- display forces as labels for selected weld parts;
- display moments as labels for selected weld parts;
Note: Forces and moments labels for the elemental method will display the values from all the welded nodes of the element.
- draw coordinate systems based on selected Method. Per full weld, the method uses information from the Weld Finder Tool. Per element, the method calculates a coordinate system at each node. Averaged vectors from the neighbor elements are used:
-detailed information about a single weld part, including results for each element/node.
Effective Plate Width - calculates effective plate width for a stiffener subjected to longitudinal, transverse and shear stress according to DNV-RP-C201 Buckling strength of plated structure, Chapter 7.3 Effective plate width. Also, it calculates η coefficient (formula 7.37) from chapter 7.5.2 Torsional buckling of stiffeners.
To edit Effective Plate Width executefrom the main menu:
Select Load using Load Selector Control and press . List of all sections with stiffeners and their related plates will be shown.
- highlight selected plates/stiffeners;
- preview selected plates/stiffeners;
It is possible to display plot with results as labels:
To see the details of the calculations select a single plate and press :
Related Stress Gradients - is calculated to reduce peak stresses at the defined points of the model.
Calculations are based on normal and shear stress amplitudes at the reference point and point below the surface according to Equation 4.3.16 of Analytical Strength Assessment of Components in Mechanical Engineering, 5th Edition, 2003:
σ1a, τ1a - stress amplitudes at the reference point;
σ2a, τ2a - stress amplitudes in a distance Δs;
Δs - the distance between the reference point and the neighboring point below the surface;
Note: Stress Gradient is calculated on free edge nodes of shell elements for their top and bottom points of interest.
To edit Stress Gradient executefrom the main menu.
Select Load Group using Load Selector Control.
- edit selected condition;
- copy selected conditions;
- remove selected conditions;
- highlight selected conditions on the model;
- preview selected conditions on the model;
Define conditions and pressto display results.
Stress Gradient Conditions
Stress Gradient is calculated for each point of interest (top and bottom) of all reference nodes. The condition can be added by the following types:
Selector Control to find free edge nodes automatically (reference points) and take neighbor nodes (points below the reference point) from the selected elements to calculate stress gradient coefficient:- select elements using
Selector Control to find free edge nodes automatically (reference points) and take the opposite points of interest for each node (points below the reference point) from the selected elements to calculate stress gradient coefficient:- select elements using
- pick reference/related elements and set points below the surface manually:
- pick element/node from the model;
- update the list of nodes of Related/Reference element;
- apply selected related node to all selected reference nodes in the list;
Related Element - stresses at the related nodes will be taken from this element. Pick an element from the model or set manually;
Reference Element - list of reference nodes will be recognized automatically from the free edges of the element. Stresses at the reference nodes will be taken from this element. Pick element from the model or set manually;
Related Nodes - points below the surface to calculate the stress gradient;
Reference Nodes - reference points to calculate the stress gradient;