In this article, a heavy cargo box is calculated according to the guidelines of the German Bundesverband Holzpackmittel (HPE). The load cases for Handling by Crane and Sea Transport are calculated.
In the case of wall-like load-bearing behavior of the cross-laminated timber plate, special attention must be paid to the shear deformation in the plane of the pane and thus, in particular, to the displaceability of the fasteners.
The support of the cross-laminated timber panel deserves special attention. Usually, a cross‑laminated wall is secured against shearing by means of shear connectors and against lifting forces by means of tie rods.
One of the advantages of entering the structure in RFEM is the complete freedom when selecting the geometry. You can easily select a structure where re‑entrant rolling corners are given as shown in the image.
In RFEM, orthotropic plastic analyses using the Tsai‑Wu plasticity criterion have been possible for quite some time now. The hardening modulus Ep,x or Ep,y can be used to consider the hardening of the material during the iterative calculation.
To better distinguish between the different layer compositions (for example, for walls and ceilings), you can assign user‑defined colors and textures to each composition.
For cross‑laminated structures with large spans, downstand beams or hybrid structures are often used. They can be modeled in RFEM 5 by using surfaces and member cross‑sections. In both structural systems, curved downstand beams are also possible without any problems. In the case of the curved surface, the member is always appropriately generated by means of the automatic member eccentricity with the thickness distance of the surface and the member. The downstand beam can also be connected flexibly by means of a line release.
In the course of a reasonable pre-dimensioning of cross-sections, you can optimize the cross-sections of the corresponding section series in the RF‑/TIMBER Pro add-on module.
In this article, we will look at the design of shear connectors of cross‑laminated timber structures that transfer the longitudinal forces of the shear wall to the soil.
Usually, the lifting forces acting on a structure, which mostly result from wind loads or a dynamic analysis, are transferred into the ground through ties.
The RX‑TIMBER stand-alone program offers you the option to optimize the lateral-torsional bracing. With this selection, the program iteratively determines the required minimum length of the lateral-torsional bracing.
In the "Material Model - Isotropic Nonlinear Elastic" window, you can select the yield laws according to the von Mises, Tresca, Drucker-Prager, and Mohr-Coulomb yield rules. This makes it possible to describe the elasto-plastic material behavior. The yield function depends on the principal stresses or the invariants of a stress tensor. The criteria apply to 2D and 3D material models.
The calculation of timber panels is carried out on simplified member or surface structures. This article describes how to determine the required stiffness.
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.
This article deals with considering end releases between surfaces with line hinges and line releases. End releases between surfaces are taken into account using line releases as well as line hinges. The examples are joints in reinforced concrete structures and frame joints in cross-laminated timber structures.
RF-/JOINTS Timber – Timber to Timber allows you to design main-connected beam joints. This article explains the determination of forces in screws of a beam connected to a torsionally rigid main beam.
Strain hardening is the material ability to reach a higher stiffness by redistributing (stretching) microcrystals in the crystal lattice of the structure. A distinction is made between the material isotropic hardening as scalar quantities or tensorial kinematic hardening.
One of my earlier articles described the Isotropic Nonlinear Elastic material model. However, many materials do not have purely symmetrical nonlinear material behavior. In this regard, the yield laws according to von Mises, Drucker-Prager and Mohr-Coulomb mentioned in this previous article are also limited to the yield surface in the principal stress space.
Composite beams in a three-dimensional analysis are usually connected with orthotropic plates. In that case, the longitudinal direction of the plate stiffness is defined by a main beam and the transverse direction by an orthotropic plate. The stiffness of the plate in the longitudinal direction is set almost to zero. This article explains the determination of stiffnesses in the orthotropic plate.
The RF‑LAMINATE library now includes the Kerto‑Q product by the company Metsä Wood. All LVL panels are available, including the characteristic strength parameters.
In the H - Roofs category, imposed loads have to be applied. These are usually the technician loads for construction and maintenance. Since there is no maintenance for snow, category H must not include both snow and imposed loads together. You can consider thi in the options for automatic combinations.