Celotipia

In this sheet all the load cases and the corresponding loads can be input and modified.

" Click on the tab and one obtains the following tab sheet:

List of actions

active load case

load case handling

input of load objects

select active load case switch to next/pervious load case check/reset loads scaling factor for 3D view Load import legend of load data

We want to introduce the following load cases for our example:

S Dead load, consisting of the selfweight of the slab and a uniformly distributed load of 0.6 kN/m2 for the surfacing

S Live load of 2 kN/m2 _{(Category A) field−wise unfavorable on four fields.}

The first load case with the selfweight is automatically generated by the program and set as the active load case. For the load case, the self−weight is realized with a accelera tion load for the mass of the slab, with the mass calculated form the volume of the slabs and the mass per unit volume of the concrete material (see menu: Settings>Materials).

All we have to do is add the surface load:

" Use for this the symbol for uniformly distributed loads and set the value of the load in the dialogue to −0.6.

. Due to the global coordinate system, in which the Z-axis points upwards, the downwards act- ing loads, inclusive of the value for the body force, have to be input with a negative sign.

" Click on the button [hole structure] and place the box somewhere inside the outline of the slab.

4 load rectangles

lowing dialogue window appears:

load case type (cannot be chan ged later)

description short id

A correct input of the action cate gory and subcategory allows a pro per automatic generation of limit state specifications

Note: The avaiable actions depend on the structure type

" Set the input fields according to the dialog shown.

Now the newly created load case is active for input. The symbols for inputting load ob jects are also now active in the tab sheet.

" Click on the symbol for area loads and set the load value to −2.0 kN/m2.

" Now draw with the rectangle tool of the Graphics Editor the four load rectangles, which together cover the whole slab.

If you click on the button twice, the rectangle tool will stay active and you can input multiple rectangles easily. To quit this mode press the ESC key.

From the Generator load case just defined, which for the subsequent solution is auto matically marked as inactive, the program generates as many individual load cases as were defined, in our case 4, named after the generator GU in the form of GU%Fx. . If afterwards one wants to modify the generated load cases, one always has to make the correc-

tions in Generated Load Case. CEDRUS-5 regenerates the corresponding load cases on leav- ing Generated Load Case each time.

. To simplify matters, the input load cases can be drawn without any difficulty over openings and also across the slab boundaries. The program only considers the load on the effective slab area.

" Click on the symbol EList of load cases" and one can see a list of the previously defined and generated load cases. The Inactive symbol with the Generator is switched on. . Besides the generator ’unfavorable pattern’ a second named ’moving load’ is supported by

CEDRUS. In that case you input a series of load objetcs (e.g. the load pattern of a truck) and a nubmer of positions, where this load objects should be placed. CEDRUS will automatically generate a load case for each position and make proper (i.e. exclusive) superposition of these load cases in the limit state specification.

A 3 Working with CEDRUS-5 Part A Base Module

The Dialog ’Actions’

" Click on this button in the tabsheet to open the list of ac tions.:

The dialog shows all actions, that have been assigned to load cases. If you want to use actions, that are not available for selection in the load case dialog, you can define them here.

The actions and their partial safety factors are used for the automatic generation of limit state specifications. For details see Chapter A 2.3 as well as the online help. of this dialog.

If you check all the actions in the dialog you will notice, that the action ’Live load gen eral’ you didn’t specify so far is listed. This action was automatically introduced for the socalled ’load transfer’ mechanism, i.e. export of the reaction forces to the floor below where you can import them. All load cases with the property ’export automatically’ turned on (=default) are combined to socalled ’export combinations’ and exported for the next floor. So by default you don’t have to do anything to export your reactions. If you want the self−weight of the columns and walls to be included in the exported loads, make sure you activated the checkbox ’Consider weight of ..’ in the property dia logs of the walls and columns! For more details check the chapter A 2.4 of this manual.

The Dialog ’Load Import’

As discussed in the last section, by default no steps must be taken for export of the reac tions of a slab. However, in order to import these reactions in the floor below, there you must define the floor that resides above yours. This is done in the dialog ’Load Im port’: