- #1
pyroknife
- 613
- 3
I am trying to select a bolt for a butt joint connection. When you guys do bolt selection, are there certain equations you use to determine if the bolt will rigidly hold the 2 parts together in the joint?
Thanks for the reply. That is very much like what I tried. Say the side area and end area are 1 in^2. That means the shear and tensile force are 100lb. Assuming 4 bolts means each bolt should handle 1/4*100=25lb.Baluncore said:http://en.wikipedia.org/wiki/Bolted_joint
Google bolt strength and see what you get...
The internal pressure of 100 psi will push the sides and the ends of the box apart. There will be a similar, if not greater force on the base of the box.
The force on the end of the box will be the end area in square inches multiplied by the internal 100 psi. The four bolts shown will have to handle that tensile force. Each will carry one quarter of the total.
http://en.wikipedia.org/wiki/Tensile_strength
The force on the side of the box will be the side area in square inches multiplied by the internal 100 psi. The four bolts shown will have to handle that shear force, each must carry one quarter of the total.
http://en.wikipedia.org/wiki/Shear_strength
Since the shear strength of a steel bolt is usually taken as 58% of the tensile strength, the box may be strongest if you put the bolts into the ends from the longer sides. But that will depend on the base and the lid attachment.
Ouch. Be careful what you are using for areas in your calculations. It is the surface area of the end and side pieces that determines the load on the bolts, not the end cross section areas. If your box is say square with 10 inch long side and end pieces each 5 inches high, your area to use is 50 in^2 not 1 in^2.pyroknife said:Thanks for the reply. That is very much like what I tried. Say the side area and end area are 1 in^2.
A butt joint is a type of joint used to connect two pieces of material together in a straight edge-to-edge configuration. It is commonly used in woodworking and metalworking.
Bolt design is important for butt joints because it determines the strength and stability of the joint. The right bolt design can ensure that the joint can withstand the expected load and prevent failure or separation of the two pieces of material.
When designing bolts for butt joints, factors such as the material and thickness of the pieces being joined, the expected load or stress on the joint, and the environment in which the joint will be used should be taken into account. It is also important to consider the type of bolt, such as a standard bolt or a specialized bolt like a lag bolt or carriage bolt.
The appropriate bolt size for a butt joint can be determined by considering the thickness of the material being joined and the expected load on the joint. Generally, a larger bolt diameter and higher grade (strength) bolt will be needed for thicker materials and heavier loads. It is also important to consider the spacing of the bolts and the number of bolts used in the joint.
Some common mistakes to avoid when designing bolts for butt joints include using bolts that are too small or weak for the expected load, not using enough bolts to evenly distribute the load, and not properly tightening the bolts. It is also important to consider the materials being joined and to use appropriate bolts for the specific type of joint being created.