Module "Compression perpendicular to grain"

The input is divided into:

• definitions of the cross section
• definitions of the plate dimensions
• input of the loads
• type of load configuration
• calculation options

An option for a quick control of the input data is offered by a graphical representation shown on the right side.

The plate is specified with its dimensions in x and y direction. The plate length is defined with dimension in x direction and the plate width with dimension in y direction.

In addition to plate dimensions, the analysis also considers the way the lamellas are joined into individual layers. Regarding to the joining of the outer layers, one should differ:

• side gluing of lamellas,
• assembly without adhesive where lamellas are placed side by side without the sheduled gaps or the expected occurence of cracks and
• possible occurence of gaps or cracks wider than 1 mm.

The applied force F_c,90 (design value) in [N], as well as the design factors can be specified here.

The load situation is described by specifying the load introduction above and below. Thereby, one can define if the load is even applied, and if so, if it is applied locally or continuously (over entire surface).

If the load is applied locally, it needs to be defined by entering the dimensions of the load surface (length l_1,2 in direction x and width w_1,2 in direction y) and the position. The position is defined as the distance between the center of a load surface and the origin of the coordinate system (lower left corner of the plate). Currently, centers of the top and the bottom load surface are coupled and cannot be moved relative to each other.

In the calculation options, the load distribution angles for longitudinal layers α₀ and cross layers α₉₀ can be changed, and for one-sided load introduction, it can be specified, in which depth (= k_ls ⋅ t_CLT) the effective area is to be determined.

The minimum load introduction area A_c,min describes the reference area in order to get the effective area A_ef,max by multiplying with the factor k_c,90. For different load introduction areas on each side it is the intersection of these two areas. The effective area A_ef,max is described by l_ef and w_ef in depth z.

The utilisation ratio for compression perpendicular to grain is indicated by η_c,90 in [%].

The following figure shows the distribution of the effective area A_ef,max over the cross section (red line) as well as the assumed load distribution (blue line).

Compression perpendicular to grain - Verification

Model for the determination of the kc,90 factor