How to model a simple Warren Truss using structural analysis software
Course: Análise estrutural (3º ano)
Modelo de amostra: Simple-Warren-Truss.s3d
Structural analysis software is a powerful tool for any structural engineer. Ele oferece aos engenheiros uma maneira fácil de modelar uma treliça e usar o Método dos Elementos Finitos para calcular as forças internas de cada membro. No plano de aula de hoje, vamos aprender a modelar uma treliça em um software de análise estrutural – and learn the various technical significance of what we are building. SkyCiv’s lesson plans are a great
Modeling our Truss
A truss is a structure commonly used in structural engineering. If you are unfamiliar with it, visit our previous article on tipos de estruturas de treliça.
To begin modeling our truss first open your structural analysis software, we can either use SkyCiv Truss (simplified 2D version) or SkyCiv Structural (3D, more powerful). Both are available from our Painel. Once you’ve opened the software, abrir Nós on the left-hand screen, e comece a inserir as coordenadas de seus nós. These are the start and endpoints of each member. Estamos tentando mapear as dimensões de nossa treliça, para modelar essencialmente a treliça. Você pode fazer isso inserindo um de cada vez, but I have chosen to use the datasheet so I can see all my node input and copy and paste:
Próximo, we will add members by connecting the nodes by clicking and dragging entre os nós:
Por padrão, SkyCiv Truss dará a todos os membros uma conexão fixa. Isso é indicado por um pequeno ponto preto que, se você passar o mouse sobre ele, mostrará “FFFFRR”. Em 3D Estrutural, voce terá que altere manualmente todas as Fixações Inicial e Final para “FFFFRR”. É essencial que todos os seus membros estejam fixados, ou os resultados da sua análise de treliça podem estar errados. Lembrar, a qualquer momento, você pode fazer login e revisar nosso modelo de amostra Simple-Warren-Truss.s3d to see this example.
[ícone ícone = 'informações'] Uma nota rápida sobre conexões fixas
Uma treliça deve ter todas as fixações do membro definidas como fixadas. What this means is that each member is free to rotate and the transfer of forces is all in axial. A quick way to check if your model is set up correctly is when you solve it – all bending moment member forces should be 0.
Click here to learn more about hinge connections ->
An easy way to make this change is through the datasheet. When you apply, you should see the little black dots on your members (SkyCiv Truss will have these on by default):
confira sua documentação de software
Em engenharia estrutural, we need our models to be Você pode se lembrar de suas aulas de física da escola que existem duas classes de atrito. No momento, our truss is not connected to anything, so if we apply loads to it there is nothing holding it still. Supports are our boundary conditions – they are what stop the truss from moving when loads are applied. Think of a truss bridge, at either end, it is connected to the land. Supports also have fixity codes to them – these indicate how the truss is supported. Por exemplo, roller support means the truss can move left to right (ou seja. pode translate in the x-direction).
It’s sometimes important to apply a roller-support on one side of a bridge, so that the structure has a bit of “give”, in case it expands. Então, on our left side, we will give our bridge a Diferentes tipos de suportes estruturais and on the right side, we will give it a roller-support. To add this, Clique no Apoia button on the left screen:
Our Truss is now sufficiently supported, we can now proceed with applying loads.
Aplicação de cargas
Loads are the forces in which the truss is to withstand. Por exemplo, the truss may be required to take the load of a 2T truck, so we need to use the software to simulate these forces and ensure the truss is safe for construction. Here we will add some distributed loads on the top chord of our structure:
Reviewing Your Results
Once you’re happy with your Truss, clique Resolver in the top right corner. In S3D it might prompt you to add a section, just click Repair for some nominal section properties. Observação: if you need to add section properties, you can do this via Seção, but in looking at reactions at supports and axial force, the section properties shouldn’t really affect your results.
If everything is set up correctly, you should be able to click Axial to review your axial force results. An axial force is the force applied as either tension (member being pulled apart) or in compression (member being pushed in). Generally dealing with trusses – axial force is the most important result.
Since the members are all pinned and free to rotate, it means that internal forces should all be axial. We can confirm this by looking at the bending moment results. Apart from the top members (who have distributed loads on them), all the members in the system have 0 bending moment forces. This is because the only forces in the members are axial:
Calculadora SkyCiv Truss
SkyCiv Calculadora Truss grátis é uma ferramenta de projeto de treliça que gera as forças axiais e reações de estruturas de treliça 2D ou vigas completamente personalizáveis. Ou para aproveitar ao máximo nossos poderosos Software Truss, inscreva-se hoje para começar!
