Big Robot- Lattice boom crane - calculating maximum stress

In summary, it appears that the bending stress of a lattice boom crane design can be calculated by taking into account the Effective Length, Fitting Stability curve, and material specifications.
  • #1
bigrobotworx
2
0
Hello brilliant engineers.

How to calculate the bending stress of a lattice boom crane design?

It’s clear how to calculate a single chord in a lattice box, at least as a cantilevered tube. However, when placed in a box lattice what is the proper approach?

I’m constructing this crane in conjunction with a big robot dragon. The “crane” is a telescoping tail that supports both riders and an aerial performer. The tail has two boom sections of 10 feet each, for an extended length of about 18 feet.

I’m attempting to determine the material specifications of the tube cords and lattice dimensions to operate the fully cantilevered working load, say 400 pounds, with a high safety factor (7x failure) to account for dynamic force and fabrication quality.

I believe the first 10 foot section can be calculated at 18 feet. Then the second section can be calculated at 8 feet independently.

Please help me understand the general approach. If there is a general rule between cords in a lattice configuration. And what formula to use, if it can be calculated manually.

I’m not an engineer. But can follow the math in https://www.physicsforums.com/threads/cantilever-beam-calculation.992690/

My eternal thanks and invitation to ride a big robot to any that can get me on the proper track!
 

Attachments

  • 42EEE2FB-8F29-4700-A59C-506A8A97F25F.jpeg
    42EEE2FB-8F29-4700-A59C-506A8A97F25F.jpeg
    37.4 KB · Views: 84
Engineering news on Phys.org
  • #3
Truss structure like this one are calculated in a different manner (with assumptions that only axial loads are carried by members, joints are hinged and external forces act only at the joints). Maybe the literature about hoist and crane devices will be helpful.

However, manual calculation will be quite tedious in this case. It would be beat to use numerical approach (finite element analysis). Here’s a similar example:
https://abaqus-docs.mit.edu/2017/En...gargocrane.htm#simagsa-c-bmsexamplegargocrane
 

1. What is a Big Robot Lattice boom crane?

A Big Robot Lattice boom crane is a type of heavy-duty crane that is used for lifting and moving heavy objects, typically in construction or industrial settings. It is characterized by its lattice boom, which is a structure made of interconnected beams that can extend and retract to different lengths.

2. How is the maximum stress of a Big Robot Lattice boom crane calculated?

The maximum stress of a Big Robot Lattice boom crane is typically calculated using mathematical formulas and computer simulations. Factors such as the weight of the load, the length and angle of the boom, and the material properties of the crane are taken into account to determine the maximum stress that the crane can withstand.

3. What are the potential risks of exceeding the maximum stress of a Big Robot Lattice boom crane?

Exceeding the maximum stress of a Big Robot Lattice boom crane can lead to structural failure, causing the crane to collapse and potentially causing injuries or damage to property. It can also result in costly repairs or replacements of the crane.

4. How can the maximum stress of a Big Robot Lattice boom crane be reduced?

The maximum stress of a Big Robot Lattice boom crane can be reduced by using lighter materials for the crane, properly maintaining and inspecting the crane for any signs of wear or damage, and following weight and load capacity guidelines set by the manufacturer.

5. Are there any safety regulations or standards for operating a Big Robot Lattice boom crane?

Yes, there are safety regulations and standards set by organizations such as OSHA (Occupational Safety and Health Administration) and ASME (American Society of Mechanical Engineers) for the operation of Big Robot Lattice boom cranes. These regulations include proper training and certification for crane operators, regular inspections and maintenance of the crane, and following weight and load capacity guidelines.

Similar threads

Replies
7
Views
2K
  • Mechanical Engineering
Replies
11
Views
2K
Replies
6
Views
4K
Replies
5
Views
4K
  • Engineering and Comp Sci Homework Help
Replies
10
Views
59K
Back
Top