The connection is made using a bolt and nut and two washers....

The connection is made using a bolt and nut and two washers. If the allowable bearing stress of the washers on the boards is $\left(\sigma_{b}\right)_{\text {allow }}=2 \mathrm{ksi},$ and the allowable tensile stress within the bolt shank $S$ is $\left(\sigma_{t}\right)_{\text {allow }}=18 \mathrm{ksi}$, determine the maximum allowable tension in the bolt shank.The bolt shank has a diameter of 0.31 in., and the washers have an outer diameter of 0.75 in. and inner diameter (hole) of 0.50 in.

Key Concepts

Allowable Stress Design (ASD)

This concept refers to designing structural components such that the stresses induced by applied loads do not exceed pre?determined allowable limits. The approach, common in engineering design, ensures that each component is safely loaded by checking that the applied loads remain within accepted stress limits, accounting for uncertainties and safety factors.

Bolted Connection Design

Bolted connection design involves the selection and arrangement of bolts, washers, and nuts to transfer loads between connected structural members. It requires understanding the load paths, ensuring that both the fastener and the connected materials (such as plates or boards) have sufficient strength to resist applied forces. The design must account for various failure modes including tensile failure of the bolt and bearing failure at the contact between the washer and the connected material.

Tensile Strength of Fasteners

This concept pertains to the maximum tension a fastener such as a bolt can withstand before failure. It is primarily determined by the cross-sectional area of the bolt and the material’s allowable tensile stress. In design, calculating the tensile capacity of the bolt is crucial to ensure that it can safely carry the intended load without yielding or fracturing.

Bearing Stress and Contact Area

Bearing stress relates to the pressure exerted on a material at the interface with another component, such as the contact between a washer and a board. The effective bearing capacity is a function of both the allowable bearing stress and the effective contact area. Accurate assessment of this area is essential to ensure that the material beneath the washer can sustain the applied loads without excessive deformation or failure.

Load Distribution in Connections

In bolted connections, the applied load is distributed between different components, such as the bolt itself and the contacting surfaces of the washers and boards. Understanding how the load divides between these elements under tension is fundamental for ensuring that no single component is overloaded. Designers must consider both the tensile capacity of the bolt and the bearing capacity of the washers to determine the maximum safe load that the connection can support.

Transcript

Please give Ace some feedback