Contents
Can a rigid body have a point mass?
Neither point masses nor rigid bodies can physically exist, as no body can really be a single point with no extent, and no extended body can be exactly rigid. Despite this, these are very useful models for mechanics and dynamics. All points on a rigid body have the same angular rotation angles, as we can see on the figure below.
Can a analytical surface be part of a rigid body?
Analytical surfaces can also be made part of the rigid body, whereas any surfaces based on the nodes or elements of a rigid body are associated automatically with the rigid body. The motion of a rigid body can be prescribed by applying boundary conditions at the rigid body reference node.
How are the elements of a rigid body accounted for?
Contributions to a rigid body from mass, rotary inertia, and heat capacitance elements are accounted for automatically when these elements are connected to nodes that are part of the rigid body. A list of nodes that are part of a rigid body is generated automatically when you assign elements to a rigid body.
Can a rigid body be declared a flexible body?
If connector elements that activate material flow degree of freedom at nodes are included in the rigid body, the material and flow through the rigid body as that degree of freedom is constrained to the motion of the rigid body. The following elements cannot be declared as rigid:
How are three rigid bodies coupled by pins?
Three rigid bodies (two rods and a block) are coupled by pins at O O, P P, and Q Q as shown. Body B 3 B 3 cannot rotate and must slide horizontally along the ground. The rod lengths are O P = 3 √ 2 m O P = 3 √ 2 m and P Q = 5 m P Q = 5 m, and points O O and Q Q are the same height above the ground.
How tall is a rigid body B 3 b 3?
Body B 3 B 3 cannot rotate and must slide horizontally along the ground. The rod lengths are O P = 3 √ 2 m O P = 3 √ 2 m and P Q = 5 m P Q = 5 m, and points O O and Q Q are the same height above the ground. At the instant shown, θ 1 = 45 ∘ θ 1 = 45 ∘, ω 1 = 4 r a d / s ω 1 = 4 r a d / s.
Why do all points on a rigid body have the same angular velocity?
All points on a rigid body have the same angular rotation angles, as we can see on the figure below. Because the angular velocity is the derivative of the rotation angles, this means that every point on a rigid body has the same angular velocity →ω