Using Pro/ENGINEER Wildfire 2.0 you can add fastener connections in structural simulation that can provide assembly connectivity/load transfers and baseline connection design feedback. In this tip, you will find out how to apply bolted connections and interpret the results.
The following three types of bolts can be defined:
1. Screw Fastener
2. Through Bolt in Solids
3. Through Bolts in Shells
Additional settings allow for basic and advanced bolts. Stiffness for basic bolts is defined by material and diameter. Advanced bolts support the following attributes:
Tensile Force (Only if Preload is defined)
Tensile Stress (Only if Preload is defined)
Separation Area Stress – If “Fix Separation” is set, let’s you know if the bolt is in tension. More details in Screw Fastener Description
Rotational degree of freedom along the bolt axis may be specified as free or fixed.
Shear stiffness may be disabled.
Here is a description of how the different types of bolt connections are defined:
Screw Fasteners (Blind Bolts)
Bolt Fasteners in Solids (Through Bolts)
The “head” of the bolt is created where the first curve is selected
The second curve selected is where the nut rests against the second component (Figure 3)
Bolt Fasteners in Shells
Selection order is not important
There must be a gap between the parts if they are quilts; fasteners cannot be zero-length
The following example shows how to add screw connections to flanges (see Figure 4):
In this case we can apply cyclic symmetry and mirror symmetry since the assembly is axially symmetric and the blue pipe is also symmetric about the center plane (Figure 5). In Figure 6 a pressure load of 10 N/mm2 is applied to the inside surface of the ‘pipe’.
Now the bolt fastener can be applied to the hole. We will select a simple bolt fastener first. Notice how the outside edges of the hole going through the two parts are selected. In this case this is a bolt and nut fastener in a thru hole (Figure 7).
Bolts have a dedicated icon. When we apply the mesh, you can see how it is mapped to the bolt geometry. This enables the program to do a “compression” only contact analysis where the bodies meet (Figure 8).
At this stage the analysis is ready for a static analysis run. As we see from the results the stress is mainly concentrated in the fillet and not the bolt hole. This is because there is no preload in the bolt (Figure 9).
Now the bolt will be modified to an advanced bolt so preload can be included. In this case the preload force will be 40000 N. The Fastener and Nut diameter can also be adjusted (Figure 10).The option to fix rotation is also available.
The results show the stress is concentrated around the bolt hole as expected. Also notice the high contact stress and effects of the Head and Nut on two components (Figure 11).
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