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000870
2025-03-04

Total Vibration of Harmonically Excited System

Bewegungsgleichung eines harmonisch angeregten Systems mit einem Freiheitsgrad

u(t) = e-ζωnt A · cosωDt + B · sinωDt⏟ + (C · sinωt + D · cosωt)⏟
                               transient                                      steady-state

t

Zeit

ω

Erregerkreisfrequenz

ωD

Eigenkreisfrequenz

ζ

Dämpfung

A

Konstante

B

Konstante

C

Konstante

D

Konstante
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Comparing Deformations of Bernoulli Beam and Timoshenko Beam
In current literature, the formulas used to determine internal forces and deformations manually are usually specified without considering the shear deformation. The deformations resulting from shear force are often underestimated in timber construction in particular.
Structural System
The calculation of timber panels is carried out on simplified member or surface structures. This article describes how to determine the required stiffness.
Framing
The stiffening of timber structures is usually carried out by means of timber panels. For this purpose, structural components consisting of slabs (chipboard, OSB) are connected with members. Several articles will describe the basics of this construction method and the calculation in the RFEM program. This first article describes the basic determination of the stiffnesses as well as the calculation.
Influence of Duration of Action on Design Value of Strength
In addition to determining loads, some particularities concerning the load combinatorics in timber design have to be considered. Contrary to steel structures, where the largest loading results from all unfavorable actions, in timber construction, the strength values depend on the load duration and timber humidity. Special characteristics have to be considered as well for the serviceability limit state design. The following article discusses the effects on the design of wooden elements and how this is possible with RSTAB and RFEM.
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Product Features
Feature 002901 | Plywood Materials According to ANSI/APA PRG 510 Plywood Standard (USA/CAN) in RFEM Material Library

In the material library of RFEM, you can find plywood materials according to the US and Canadian standards ANSI/APA PRG 510 Plywood (USA/CAN).

Feature 002870 | Charring Diagram

For the fire resistance design of timber surfaces, you can display a charring diagram depending on the time of fire exposure.

It is also possible to print this charring diagram into the printout report.

Feature 002824 | OSB Material for USA and Canada

In RFEM, the oriented strand board (OSB) material is available for the USA and Canada. The material parameters are taken from the "Panel Design Specification manual".

Feature 002792 | Visualization of a timber panel element, modeled with the Beam Panel thickness type for structured 3D models.

Using the "Beam Panel" thickness type, you can model timber panel elements in 3D space. Simply specify the surface geometry and the timber panel elements are automatically generated using an internal member-surface construct, including the element connection stiffness. The Beam Panel thickness type is defined using the Multilayer Surfaces add-on.

A "beam panel" provides you with the following advantages:

  • Single-sided or double-sided sheathing
  • Automatic calculation of a semi-rigid coupling between studs and sheathing
    • Nailed sheathing connection
    • Stapled sheathing connection
    • User-defined sheathing connection
  • Representation as a complete geometric 3D object (frame, studs, surface, etc.), including eccentricity and automatically calculated stiffness between elements
  • Consider openings via surface cells
  • Design of the individual structural elements utilizing the Timber Design add-on (full shear wall design planned for a future release)
  • Other material options available (e.g., particle board, gypsum, or fiberboard sheathing with cold-formed steel sections)
Frequently Asked Questions (FAQ)
Is it possible to model a semi-rigid composite beam with a line release using members in RFEM?

Do I need to add a line hinge/line release for the CLT wall-to-floor connection in the Building Model add-on?
How can I add counteracting dead loads (0.9*D) in NBC load combinations?
How can I perform member design by case for different settings in the design configuration?
How can I exclude the dead load in NBC load combinations when performing a deflection check?
What is the conservatism factor for CLT in Timber Design?
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