what type of material is this equation apply on? And is there any engineering way to prevent the physical limitation?

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If the material is subjected to triaxial stress, What does each principal stress contribute?

A machine element in a packaging machine is subjected to a tensile load of 36.6 kN that will be repeated several thousand times over the life of the machine. The cross section of the element is 12 mm thick and 20 mm wide. Specify a suitable material from which to make the element. 47

How and Why is the Hardness of Mineral important in Civil Engineering? Provide a thorough discussion

A steel bar has a length of 2.5 m and cross-section of 200-mm x 100-mm. The modulus of elasticity of this material is 210 GPa and Poison's Ratio is 0.3. The change in width after applying a tensile force of 150 kN is?

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A steel bar with a length of 3 m, diameter of 25 mm, modulus of elasticity of 207 GPa, and linear coefficient of thermal expansion of 0.000009 m/m/°C is fixed at both ends when the ambient temperature is 40°C. If the ambient temperature is decreased to 15°C, what internal stress will develop due to this temperature change? Is this stress tension or compression? Why?

It is desirable that the in-place material possess certain properties. What are the properties describe.

How and Why is the Cleavage of Mineral important in Civil Engineering? Provide a thorough discussion