Analysis

Analysis

The analysis of the 3Muri structure is divided into two phases: in the first the equivalent frame model is automatically generated, in the second the non-linear static analysis (push-over) is performed from which the capacity curve of the structure is obtained ( stress curve – control point shift).

The result of the generation of the equivalent frame model is the presentation of a mesh that schematizes the structure in males, bands, beams, tie rods, and pillars. These elements can still be manually modified to take account of particular situations.
The non-linear analysis, on the other hand, is conducted by monotonously increasing the loads, and obtaining the horizontal displacement of the structure. By exceeding a conventional value of displacement, calculated automatically, the collapsed structure is considered and the horizontal force – horizontal displacement curve can be constructed, which represents the offered capacity curve, i.e. the behavior of the structure as the horizontal loads vary.

Graphic area dedicated to the analysis and presentation of results

Automatic mesh

The 3muri software allows the automatic determination of the equivalent frame, once the geometry of the building has been defined, through an algorithm that recognizes the connections between the wall panels and divides them into rigid elements, males, bands and creating the structure to be analyzed.

Thanks to an evolved meshatore, designed specifically for masonry, even very complex situations can be taken into consideration, with always correct and reliable engineering results.
Below, an automatically schematized structure with the equivalent frame is presented, therefore with the automatic determination of taps, bands and rigid elements, where the openings, neighboring walls and external constraints are taken into account.

Nonlinear Analysis – Pushover

3Muri allows interoperability with the BIM methodology through the IFC (Industry Foundation Classes) format, whose specifications are based on a neutral data format specifically designed to describe, exchange and share project information.

3Muri provides for the import of geometries from IFC models thanks to the BIM Inside application, included in the module. In this way the geometries of the objects can be used for the construction of the model.

For each analysis, the push-over curve and the bilateral schematic of the equivalent system are presented. Depending on the selected standard, the corresponding test conditions are displayed.

It is possible to examine any parameter of the construction response, in order to have an adequate understanding of the structural behavior. These data are necessary to better plan any seismic adjustment or improvement interventions.

For each analysis, the push-over curve and the bilateral schematic of the equivalent system are presented. Depending on the selected standard, the corresponding test conditions are displayed.

It is possible to examine any parameter of the construction response, in order to have an adequate understanding of the structural behavior. These data are necessary to better plan any seismic adjustment or improvement interventions.

Representation of the stress and strain curve

The limit of the curve to the right indicates the displacement provided by the structure. The vertical red bar indicates the minimum displacement required by the standard.

If this value is less than the right limit of the curve, the structure is verified. If, on the other hand, the structure is not verified, it is possible to foresee improvements by means of plating or injections, or by inserting new elements with different materials, for example reinforced concrete partitions, beams, pillars, curbs, chains.

By operating in this way it is no longer necessary to verify the individual elements, as their contribution is implicitly taken into account in the analysis phase of the entire structure.

The 3Muri model, through the study of the elastoplastic behavior of the elements, allows to evaluate the conditions of the single elements and of the overall structure at any time. Verification is therefore obtained in terms of performance, that is, the ability of the structure to undergo displacements greater than what is required by the standard.

Results

The data window presents the values of the displacements, the stress and deformation characteristics of the nodes for the various walls that make up the structure for each subpass of the analysis. In this window, each value can be selected, and it is also possible to transmit the results to other programs (Word, Excel, etc.).

The trend of the deformation is also displayed, both of the plant and of the wall, the different color highlights the progress of the damage in the various macro elements. By observing the shades of color present in the map of the deformed wall, it is possible to easily determine the damaged macroelements and the cause of the damage (cutting, bending).

For all undamaged elements it is also possible to evaluate the tendency to damage, distinguishing whether they enter the plastic field by cutting or by pressure bending. This type of visualization does not only concern the wall elements but also those in reinforced concrete, steel or wood.

This tool shows great potential for the management of any existing adaptation interventions, as it proves to be very effective in identifying the areas in which to intervene.

Single wall analysis

Non-linear static analysis (pushover) is commonly known as global building analysis. All global analyzes require the building to have good box-like behavior.

Sometimes, design practice confronts us with cases in which the limited stiffness of the floors on portions of the structure can significantly influence the overall behavior of the building.
Walls connected to the structural context through floors of limited stiffness may make it necessary to leverage individual walls.

A new function allows you to graphically select one or more walls to be checked. For each wall the program automatically generates 4 analyzes to take into account the 2 directions for 2 different load distributions.