Once the structural engineer has defined the geometry of the structure for analysis, the next task is to apply loads representative of the loading which will be applied to the structure in use to simulate model behavior under different types of actions.
Structural loads are forces applied to a component of a structure or to the structure as a whole.
In React Structures, before you apply any loads you should define load cases. A load case represents a group of loads of the same nature, such as dead, live, wind (in one direction), snow, accidental, or seismic.
React Structures allows for the definition of many different types of loads such as nodal, linear, and surface.
When you create a new project, a self-weight load case is added automatically. It is used to apply a self-weight load to the model while you define elements of your structure.
The Load tab in the Ribbon contains all load features. If the Load Case dialog contains only an automatic self-weight load case, clicking + adds a dead load case with a consecutive number. When you add the next load cases, cells with their parameters are populated based on the last load case.
When you have added a load case you can select a nature of it using the combo box.
Natures such as: dead, live, wind, snow, accidental, or seismic are available.
Labels are created automatically and you cannot edit them. They are abbreviated names of load cases indicating their natures. For example, LL1 is a label of the first live load case in the project. You can name your load case using the Case name field.
Once you have created all your load cases it’s time to apply structural loads related to these load cases.
In React Structures Tech Preview 1 four types of loads are available:
Before you set up the parameters of your loading you should select a load case.
When you want to apply linear or surface loads to the structure you can do this in the global or local coordinate system.
In addition, you have the Global with projected load option. It specifies a load direction in the global coordinate system. You can use it to apply the load to the element length projected on the plane that is normal to the load direction.
This is often used for snow loads to reduce the load intensity when you apply loads to inclined member or surfaces.
Similar to the support definition you can use two assignment modes to apply loads to elements.
You can use the Direct mode to apply loads to elements that you select directly in the drawing area. You can select elements consistent with the load type. For example, for surface loads, you can select surface elements. You can select one element at a time. The load is applied instantly and the load contour is displayed in the model view.
You can use the Selection mode to apply loads to a selection of elements.
You can control visibility of load symbols and its values using two options in the Status bar.
Once you have applied all loads to your structure you can review them by switching between load cases using the combo box in the Object Inspector.
In order to apply wind loads you can also perform wind simulation. The wind loads simulation feature enables you to simulate a wind flow around your structure, and to generate wind loads automatically.
This feature is especially useful with structures that have a complicated geometry, and for which it is usually difficult to define the right wind loads. The wind simulation acts as a wind tunnel, and displays colored pressure maps on the model in order to help visualize and understand the effects of the wind.