Do you want to consider other loads as masses in addition to the static loads? The program allows that for nodal, member, line and surface loads. For this, you need to select the Mass load type when defining the load of interest. Define a mass or mass components in the X, Y, and Z directions for such loads. For nodal masses, you have an additional option to also specify moments of inertia X, Y, and Z in order to model more complex mass points.
Modal Analysis | Adding Masses
Do you have any questions?
Length: 00:01:27 min
Length: 00:00:34 min
Length: 00:00:00 min
Product Feature
Length: 00:00:55 min
Product Feature
Length: 00:00:35 min
Length: 00:50:32 min
Length: 00:02:35 min
Length: 00:00:00 min
Product Feature
Length: 00:00:32 min
Both the determination of natural vibrations and the response spectrum analysis are always performed on a linear system. If nonlinearities exist in the system, they are linearized and thus not taken into account. They are caused by, for example, tension members, nonlinear supports, or nonlinear hinges. This article shows how you can handle them in a dynamic analysis.
The three types of moment frames (Ordinary, Intermediate, Special) are available in the Steel Design add-on of RFEM 6. The seismic design result according to AISC 341-22 is categorized into two sections: member requirements and connection requirements.
The Steel Design add-on in RFEM 6 now offers the ability to perform seismic design according to AISC 341-16 and AISC 341-22. Five types of seismic force-resisting systems (SFRS) are currently available.
The three types of moment frames (Ordinary, Intermediate, Special) are available in the Steel Design add-on of RFEM 6. The seismic design result according to AISC 341-16 is categorized into two sections: member requirements and connection requirements.
Have you already discovered the tabular and graphical output of masses in mesh points? That's right, this is also part of the modal analysis results in RFEM 6. This way, you can check the imported masses that depend on various settings of the modal analysis. They can be displayed in the Masses in Mesh Points tab of the Results table. The table provides you with an overview of the following results: Mass - Translational Direction (mX, mY, mZ), Mass - Rotational Direction (mφX, mφY, mφZ), and the Sum of Masses. Would it be best for you to have a graphical evaluation as quickly as possible? Then you can also graphically display the masses in mesh points.
As you've already learned, the results of a Modal Analysis load case are displayed in the program after a successful calculation. You can thus immediately see the first mode shape graphically or as an animation. You can also easily adjust the representation of the mode shape standardization. Do that directly in the Results navigator, where you have one of four options for the visualization of the mode shapes available for the selection:
- Scaling the value of the mode shape vector uj to 1 (considers the translation components only)
- Selecting the maximum translational component of the eigenvector and setting it to 1
- Considering the entire eigenvector (including the rotation components), selecting the maximum, and setting it to 1
- Setting the modal mass mi for each mode shape to 1 kg
You can find a detailed explanation of the mode shape standardization in the OnlineManual here.
Do you want to consider other loads as masses in addition to the static loads? The program allows that for nodal, member, line and surface loads. For this, you need to select the Mass load type when defining the load of interest. Define a mass or mass components in the X, Y, and Z directions for such loads. For nodal masses, you have an additional option to also specify moments of inertia X, Y, and Z in order to model more complex mass points.
It is often necessary to neglect masses. This is particularly the case when you want to use the output of the modal analysis for the seismic analysis. For this, 90% of the effective modal mass in each direction is required for the calculation. So you can neglect the mass in all fixed nodal and line supports. The program automatically deactivates the associated masses for you.
You can also manually select the objects whose masses are to be neglected for the modal analysis. We have shown the latter in the image for a better view. A user-defined selection is made the and the objects with their associated mass components are selected to neglect the masses.
How do I define a plastic hinge in RFEM 6?
How can I exchange data between RFEM 6 / RSTAB 9 and IDEA StatiCa?
How can I generate an area load on members via cells in RFEM 6 or RSTAB 9?
In the Steel Design add-on, I have set the boundary conditions in such a way that the I-beam flange is restrained against the horizontal displacement. I then calculated the critical load factors using the Structure Stability add-on, but with no effect on the critical load factor value. What is the reason for this?
Where can I find my customer number in RFEM or RSTAB?
How can I define temporary supports for a form-finding process in RFEM& 6?
Recommended Products for You
RFEM 6 | Main Program RFEM 6
Main Program
The new generation of 3D FEA software is used for the structural analysis of members, surfaces, and solids.
Price of First License
4,170.00 USD
RFEM 6 | Design
Add-On
The Steel Design add-on performs the ultimate and serviceability limit state design checks of steel members according to various standards.
Price of First License
2,550.00 USD
RFEM 6 | Joints
.png?mw=600&hash=49b6a289915d28aa461360f7308b092631b1446e)
Add-On
The Steel Joints add-on for RFEM allows you to analyze steel connections using an FE model. The FE model is generated automatically in the background and can be controlled via the simple and familiar input of components.
Price of First License
2,110.00 USD
RFEM 6 | Additional Analysis
Add-On
The Torsional Warping (7 DOF) add-on allows you to consider cross-section warping as an additional degree of freedom when calculating members.
Price of First License
1,480.00 USD
RFEM 6 | Additional Analysis
Add-On
The Nonlinear Material Behavior add-on allows you to consider material nonlinearities in RFEM for example, isotropic plastic, orthotropic plastic, isotropic damage).
Price of First License
1,480.00 USD
RFEM 6 | Additional Analysis
Add-On
The Structure Stability add-on performs stability analysis of structures. It determines critical load factors and the corresponding stability modes.
Price of First License
1,300.00 USD
RFEM 6 | Additional Analysis
Add-On
The Construction Stages Analysis (CSA) add-on allows for considering the construction process of structures (member, surface, and solid structures) in RFEM.
Price of First License
1,570.00 USD
RFEM 6 | Additional Analysis
Add-On
The Time-Dependent Analysis (TDA) add-on allows you to consider the time-dependent material behavior of members. The long-term effects, such as creep, shrinkage, and aging, can influence the distribution of internal forces, depending on the structure.
Price of First License
1,030.00 USD
RFEM 6 | Additional Analysis
Add-On
The Form-Finding add-on finds the optimal shape of members subjected to axial forces and tension-loaded surface models. The shape is determined by the equilibrium between the member axial force or the membrane stress and the existing boundary conditions.
Price of First License
2,060.00 USD
RFEM 6 | Dynamic Analysis
Add-On
The Modal Analysis add-on allows for the calculation of eigenvalues, natural frequencies, and natural periods for member, surface, and solid models.
Price of First License
1,210.00 USD
RFEM 6 | Dynamic Analysis
Add-On
Using the Pushover Analysis add-on, you can analyze the seismic actions on a particular building, and thus assess whether the building can withstand an earthquake.
Price of First License
1,300.00 USD
RFEM 6 | Special Solutions
Add-On
The Building Model add-on for RFEM allows you to define and manipulate a building using stories. The stories can be adjusted in many ways afterwards. The information about stories and the entire model (center of gravity) is displayed in tables and graphics.
Price of First License
1,660.00 USD
RFEM 6 | Design
Add-On
The Stress-Strain Analysis add-on performs general stress analysis by calculating the existing stresses and comparing them with the limit stresses.
Price of First License
1,210.00 USD
RSTAB 9 | Main Program RSTAB 9
Main Program
The modern 3D structural analysis and design program is suitable for the structural and dynamic analysis of beam structures as well as the design of concrete, steel, timber, and other materials.
Price of First License
2,910.00 USD
RSTAB 9 | Design
Add-On
The Steel Design add-on performs the ultimate and serviceability limit state design checks of steel members according to various standards.
Price of First License
2,550.00 USD
RSTAB 9 | Additional Analysis
Add-On
The Structure Stability add-on performs the stability analysis of structures. It determines critical load factors and the corresponding stability modes.
Price of First License
1,300.00 USD
RSTAB 9 | Design
Add-On
The Stress-Strain Analysis add-on performs a general stress analysis by calculating the existing stresses and comparing them to the limit stresses.
Price of First License
1,120.00 USD
RSTAB 9 | Additional Analysis
Add-On
The Torsional Warping (7 DOF) add-on allows for considering cross-section warping as an additional degree of freedom when calculating members.
Price of First License
1,480.00 USD
RSTAB 9 | Dynamic Analysis
Add-On
The Modal Analysis add-on allows for the calculation of eigenvalues, natural frequencies, and natural periods for member, surface, and solid models.
Price of First License
1,210.00 USD
RSTAB 9 | Dynamic Analysis
Add-On
Earthquakes may have a significant impact on the deformation behavior of buildings. A pushover analysis allows you to analyze the deformation behavior of buildings and compare them with seismic actions. Using the Pushover Analysis add-on, you can analyze the seismic actions on a particular building, and thus assess whether the building can withstand the earthquake.
Price of First License
1,300.00 USD
RFEM 6 | Dynamic Analysis
Add-On
The Response Spectrum Analysis add-on performs seismic analysis using multi-modal response spectrum analysis. The spectra required for this can be created in compliance with the standards or can be user-defined. The equivalent static forces are generated from them. The add-on includes an extensive library of accelerograms from seismic zones that can be used to generate the response spectra.
Price of First License
1,390.00 USD
RFEM 6 | Design
Add-On
The Concrete Design add-on allows for various design checks according to international standards. You can design members, surfaces, and columns, as well as perform punching and deformation analyses.
Price of First License
2,550.00 USD
RFEM 6 | Design
Add-On
The Timber Design add-on performs the ultimate, serviceability, and fire resistance limit state design checks of timber members according to various standards.
Price of First License
1,930.00 USD
RFEM 6 | Design
Add-On
The Masonry Design add-on for RFEM allows you to design masonry using the finite element method. It was developed as part of the research project titled DDMaS – Digitizing the Design of Masonry Structures. The material model represents the nonlinear behavior of the brick-mortar combination in the form of macro-modeling.
Price of First License
1,660.00 USD
RFEM 6 | Design
Add-On
The Aluminum Design add-on performs the ultimate and serviceability limit state design checks of aluminum members according to various standards.
Price of First License
1,750.00 USD
RSTAB 9 | Dynamic Analysis
Add-On
The Response Spectrum Analysis add-on performs seismic analysis using the multi-modal response spectrum analysis. The spectra required for this can be created in compliance with the standards or can be user-defined. The equivalent static forces are generated from them. The add-on includes an extensive library of accelerograms from seismic zones that can be used to generate response spectra.
Price of First License
1,390.00 USD
RSTAB 9 | Design
Add-On
Concrete Design add-on allows for various design checks of members and columns according to international standards.
Price of First License
2,550.00 USD
RSTAB 9 | Design
Add-On
The Timber Design add-on performs the ultimate, serviceability, and fire resistance limit state design checks of timber members according to various standards.
Price of First License
1,930.00 USD
RSTAB 9 | Design
Add-On
The Aluminum Design add-on performs the ultimate and serviceability limit state design checks of aluminum members according to various standards.
Price of First License
1,750.00 USD