Rivets Strength
Table of contents
About
The “Rivets Strength” object adds the post processing features to the Rivets load object. This result object will extract all forces and moments in all rivet sections for a selected group of rivets and plot selected result on the model and create a results summary listing.
Usage
Inputs to define the Rivets Strength are defined in the table below. If selecting Rivet Code additional properties are visible and described in the Design Codes section.
| Geometry | |
|---|---|
| Scoping Method | All Bodies (Default)/Geometry Selection/Named Selection |
| Geometry | Edges from selected rivet object (i). |
| Rivet Geometry | |
| Rivet Object | Select a Rivet object from the list (ii). |
| Shaft Diameter, d | Shaft diameter used in evaluation (can be changed). |
| Head Diameter, dm | Head diameter (currently not used in evaluation). |
| Hole Diameter, d0 | Identified hole diameter (can be changed). |
| Rivet Evaluation | |
| Rivet Code | None/Eurocode 3 (Default) |
| Rivet Result | |
| Result item | Select a result item to display. |
| Calculate Time History | No/Yes (Default) |
| Scale Factor Value | Scale factor on the calculated loads, e.g. load safety factor (iii). |
| Definition | |
| By | Time (Default)/Result Set/Maximum Over Time/Time Of Maximum (standard Mechanical feature) (iv). |
| Display Time | Load step time for results evaluation (v). |
Note that “Nodal Forces” must be set to “Yes” in Analysis Settings under Output Controls in order for post processing to work. When adding the first rivet object this setting is automatically set to “Yes”.
(i) Geometry
To limit post processing to specific rivets in the group edit the geometry scoping of edges. The node numbers from the selected rivet object will be compared with the node numbers in the selection and results will only be plotted for nodes/rivets that are scooped in the selection.
(ii) Rivet Object
To avoid duplicate names the rivet object Id number is appended to the name. When selecting a rivet object the corresponding geometry is automatically selected and the rivet dimensions are retrieved.
(iii) Scale Factor Value
In a Random Vibration analysis this sets the probability of the results (1: 68.269%, 2: 95.45%, 3: 99.73%).
(iv) By
You may use Maximum Over Time to get the worst case from all steps. In addition, the Graph displays the time history of min and max for the selected result.
(v) Display Time
You may only use time steps where there are results saved, see the graph and tabular data window for load steps to use.
Result Items
| Result Item | Description |
|---|---|
| Normal Force | Absolute value of axial force at each shear plane, FtEd |
| Shear Force | Shear force sum at each shear plane, FvEd |
| Bending Moment | Bending moment sum at each shear plane, Mb |
| Normal Stress | Axial stress in rivet shaft at each shear plane, σn = Ft/As where As = πd2/4 |
| Shear Stress | Shear stress in rivet shaft at each shear plane, τv = Fv/As |
| Bending Stress | Bending stress in rivet at each shear plane, σb = Mb/Ws where Ws = πd3/32 |
| Structural Stress | Normal + Bending stress in a rivet at each shear plane, σs = σn + σb |
Output
The selected Rivet result item is displayed on each edge section for all rivets.
The rivet geometry can be visualized using the Bolt Settings property “Show Geometry on Results = Yes”.
The Rivets Result object writes a property and result csv files to the solver files directory of the analysis. These files are used by the Bolt Report features and can easily be imported to Word or Excel. You may display the output using the Worksheet Preview feature.
When solving a model with rivets the FE properties (nodes, coordinates and element numbers) are listed in the output file. This information can be written to a csv file by change the setting the Rivet Settings option “Write Rivet Data to CSV = Yes”.
When post processing a rivet group for the first time the rivet index, coordinates, section forces and moments are extracted (in the solution units) for all load steps and written to csv file. This file is used when post processing the rivets.
The location for the coordinate file and the rivet result file is the sub folder “Bolt Toolkit” in the solver files directory.