Mechanical Engineer

Posts

Stresses on Inclined Planes-II

September 11, 2016

In our analytical approach, we take several assumptions, and each of these assumptions pushes our problem in hand towards the ideal region, which may help in easily solving our problem but it also fills our solution with many errors. Our whole study of solid mechanics is based on several assumptions, but in real-life problem solving cases, these assumptions cannot be applied. However for the higher level of study we first have to clear our basic fundamentals and then approach to the next level. Giving equal importance to these assumptions is an important practice cause it help to appreciate what is really going on inside our object under observation. In this article we examine the stresses on a inclined plane. Stresses on Inclined Plane- Part II The basic element for analysing stress In my previous article of "Principal Planes and Stresses-Part I" , I have derived the expression for normal and shear stresses due to the effect of normal forces acting on any set of

Principal Planes & Stresses-Part I

August 27, 2016

The concept of principal stresses and strains is an important factor in designing of everyday machine elements or components. It is an important factor for an engineering which help in manifest an element. The true understanding of this concept will come to you by imaging the following situation: Normal force applied on a cube Suppose we have a cube in space under Cartesian co-ordinates . Now you apply some force in a particular direction say in positive x-direction. The force we applied is of finite magnitude and for a significant amount of time so the the cube is taken from its stable elastic region to plastic region. Now the cube is deformed in the direction of the applied force,i.e, the force was tensile in nature. In our case the only stress generated throughout the volume of cube is normal stress. Traction force applied on a cube Now suppose you have a cube fixed at one face and we are applying force parallel(traction force)on the face opposite to the fixed sid

Hoop Stress in Thin Spherical Shells

August 20, 2016

Application of hoop or circumferential in thin spherical shells has prime significance in daily life. Pressurized gas filled in shell Image a spherical shell in which we have pumped a gas up to significant pressure. Due to this pressurized gas, the shell will undergo volumetric expansion and stresses will be developed. Whenever we have to account for the stresses develop in any shape, we use a hypothetical cutting plane, to divided our object into sections and then examine the nature of stress developed in analytical method. However, for the experimental stress analysis there are in-numerous methods and each method can be exploited for determining specific forces. Expression: Sphere being cut into halves Consider a spherical shell with is cut into half using an imaginary cutting plane. Now the sphere is made into two halves and we analysis on one of the half. The stress will have two components. One component along x-axis and one along y-axis. We wi

Hoop Stress in Thin Cylinders

August 14, 2016

In our daily life, either technical or non-technical field, we come across object with the dominant shape of a cylinder. Looking around our-self, there are innumerous cylindrical objects, so to study the behavior of this shapes under stress has become an important aspect. Expression Cylinder subjected to internal pressure Consider a cylinder of thickness t filled with pressurized gas exerting a force on the inner walls of the cylinder. Due to pressure exertion the block undergoes volumetric expansion and stresses are being develop. Specification of cylinder: Radius r, Diameter D Thickness t Length L Small element taken for further integration We consider a small element of the cylinder, analyze the forces acting on this element and integrating the resultant to get the total force. Length of arc subtended from the center: r* 𝛅 θ Integral element under pressure Area of this element: (D/2)* 𝛅 θ * 𝛅L Small force

Questions on Stresses

July 30, 2016

Consider two beams A & B. Beam A and B are positioned in horizontal direction and vertical direction respectively. Breadth of both beams is 2 cm. Initially the setup was at a stable environment of temperature 38 o C but suddenly the temperature hits 120 o C. Beam A is weightless and beam B has a weight of W. Find the deflection of beam A. E A =2x10 5 N/mm 2 ; E B =9.65x10 6 N/mm 2 Consider the following: Two poles each carrying thick circular cross-sectional wires of diameter 2 cm are separated by a distance of 10 m. The two wires are initially loosened such that they can be imagined to be segments of a circle of radius R. Conditions arises such that the upper wire receives heat and lower wire rejects heat. The initial temperature of both the wire is same and the amount of heat absorbed and rejected by the wires is same. Both wires are carrying current I. Find the maximum temperature suc

Search This Blog