Design of a tension Brace

Design of a Tension Brace
Student’s Name
Institutional Affiliation
Introduction
The selection of the best materials for the use in the engineering purposes requires proper knowledge in the mechanical properties of the materials used. The mechanical properties of the materials include the ductility, the hardness, the resilience, the tensile strength, brittleness and the toughness of the material (Dowling 2012). The mechanical properties of most materials are affected by the microstructure of the materials used and the heat treatment properties during the metal forming process.
The tensile strength is a very common feature in the selection and the design of the engineering materials. The tensile strength involves the calculations on the shear, the bearing and the tensile stresses (Dubbel 2013).
The report aims to investigate the principles design procedures for the material selection. Again, the calculations in the finding the tensile strength, the shear stress and the bearing stresses are very critical.
Part B

From the diagram above, the failure modes of the assembly are expressed regarding the bearing, shear and the tensile stresses. The failure due to the tensile stress should occur at the center of the rod. When the rod is brought under tension, necking occurs, and the diameter of the rod decreases around the neck area while the length of the rod increases (Mazahery 2012). The rod fails when the stress reaches the fracture point.

The failure due to the shearing forces should occur at the weld regions. The shear forces will cause the weld to crack and the metal slip if the shear force surpasses the ultimate weld strength. The failure due to the bearing stress should occur at the turnbuckle. The bolting mechanism in the turnbuckle should overcome the bearing pressure generated by the tensile force at the turnbuckle joint.
The design for the turnbuckle, welding, and the rod thread area
The turnbuckle carries a tension load of (30 + X) kN. For instance, if the student number is 1234567 then the load is 30 + 67 = 97 kN.The formula for the bearing stress is given as PbAbWhere Pb is the compressive load and the Ab is the area perpendicular to the bolt.
From the data given the bearing stress is given as 300MPa and the shear strength is 50% of the tensile force while the allowable stress is 2/3 of the yield stress. For the 300Mpa stress, the diameters of the turnbuckle should be
d=300×10^64πx97=25.4 mmThe weld area is supposed to be
23 x 25.4mmx25.4mm=430mm2The following equation gives the rod thread area
P=σ×AA=πd24=π0.0224=3.145 x 10-04m2 References
Dowling, N. E. (2012). Mechanical behavior of materials: engineering methods for deformation, fracture, and fatigue. Pearson.
Dubbel, H., & Davies, B. J. (2013). Dubbel-Handbook of mechanical engineering. Springer Science & Business Media.
Mazahery, A., & Shabani, M. O. (2012). Mechanical properties of A356 matrix composites reinforced with nano-SiC particles. The strength of Materials, 44(6), 686-692.