Continuum Mechanics is the branch of mechanics which deals with the study of deformation and motion of continuous bodies. Primarily, a continuous solid body can be categorized into two types: (i) Rigid body and (ii) Elastic body. When external forces are applied on the body and the relative positions of its particles do not change at all, the body is said to be perfectly rigid body, otherwise it is said to be elastic body. A body is called strained, if under the influence of some external forces, the relative positions of its particles get altered. The change in the relative position of particles is called deformation. In practice, all solid bodies undergo deformation up to some extent by the application of suitable forces upon them. There are certain bodies which regain their original configuration when the deforming forces are removed. For example, the wire regains its original length after …show more content…
Rigid body motion does not change the length of a vector joining the pair of points inside the body and has no concern with the strain analysis. When external forces are applied on an elastic body, the body undergoes deformation. Due to the elasticity of the body, there comes into play a force which resists the deformation. This force is called stress force. Clearly, the deformation of the body is accompanied by the stress force. In other words, stress and strain occur together in inelastic body. There are two types of elastic deformation: (i) Dilatation and (ii) Shear strain set up in the body in such a way that there is a change only in volume but no change in shape, is called dilatation. In the shear deformation, there is a change in the shape of the body without a change in its volume. Dilatations are further categorized into two kinds: compression, in which volume is reduced; and rarefaction, in which the volume is
According to Neumann, a force can be considered a push or pull that can produce, arrest or modify movement and can be measured as F=ma (Neumann, 2010). Force can also be considered the load. In regards to muscle contraction force relative to the joint, the force can be the internal force produced by the muscle itself, the force of gravity or the force of the particular load/weight. Torque is a cross product between force and the distance of the force from the fulcrum and is the ability of a force to cause rotation on a lever. Torque is a measure of how much a force acting on an
Kinematics unlike Newton’s three laws is the study of the motion of objects. The “Kinematic Equations” all have four variables.These equations can help us understand and predict an object’s motion. The four equations use the following variables; displacement of the object, the time the object was moving, the acceleration of the object, the initial velocity of the object and the final velocity of the object. While Newton’s three laws have co-operated to help create and improve the study of
tension of the system. Their orientation at the interface varies, depending on the components of
General Strain Theory was reinvented by Robert Agnew in 1992 and contributed a new perception to the present strain theory that was popularized a couple eras ago (Agnew, 1992). Classic strain theory is connected; first with Merton’s (1938), Cohen’s (1955) and Cloward and Ohlin’s (1960). Founded on Durkheim’s theory of anomie (1893), Merton industrialized his theory of deviancy inside a societal fundamental context. Merton’s interpretation on the topic is that goal-expectation inconsistencies, composed with social stratification generates strain between underprivileged societies in turn leading them to use any means necessary, such as criminal, in order to accomplish socially defined goals (Merton, 1938). Merton specified that deviance was a creation of inconsistency amongst social goals and the genuine means to attain these goals (Smith & Bohm, 2008). Merton shaped a typology of deviance contingent on how diverse human beings adjust to ethnically persuaded strain. Conferring to Merton, crime can be elucidated by the predictable socially acknowledged goals and the conceivable genuine means of accomplishing them.
Muscle activity, including generating force and moving limbs through lengthening and shortening, is an important influence on beneficial tissue stress. Muscles adapt quickly to periods of lower or higher stress and demonstrate obvious visual and functional changes. At a tissue level, the Physical Stress Theory (PST) states that muscle adaptations are consistent with other high and low strain tissue adaptation models. Low stress/activity associated with immobilization results in decreases in contractile protein, fiber diameter, peak tension and power. Evidence supports the idea that tissues within the musculoskeletal system atrophy and become less tolerant of physical stress if stress on the tissue diminishes below a baseline level.3 In addition,
General Strain Theory was discussed by Robert Agnew, and first published in 1992. According to General Strain Theory individuals engage in crime because of strains or stressors which produce anger and anxiety (Agnew, 1992). Crimes become the outlet that the individual uses to cope with or remedy the strains or stressors. Agnew states that there are three different types of deviance producing strains.
It is Isometric. This means that it is performed in a static position. By so doing, the force of the muscles contracts over the bones, making them thicker and stronger.
A muscle trauma which, is also known as a muscle strain is an injury which, occurs within the muscle tendon. The pain can be classified into three different sections which are; mild, moderate and severe. The main cause of a muscle strain is when the muscle is overstretched since the muscles have probably been working too hard. If a muscle tear occurs, it can also damage the attaching tendons within the muscles because, the muscle tissues are stretched and then torn (2).
Mechanical Engineering 130.2 (2008): 6 - 7. Academic Search Complete. Web. The Web. The Web.
Chapter 14 obtain the principle of work and energy by combined the equation of motion in the tangential direction, ƩFt = mat with kinematics equation at ds = v dv. For application, the free body diagram of the particle should be drawn in order to identify the forces that do work. However, Chapter 18 use kinetic energy that the sum of both its rotational and translational kinetic energy and work done by all external forces and couple moments acting on the body as the body moves from its initial to its final position. For application of Chapter 18, a free-body diagram should be drawn in order to account for the work of all of the forces and couple moments that act on the body as it moves along the
These properties can be used for design and analysis of engineering structures, and for developing new materials that better suit a specified use. [8] Tensile tests are simple, relatively inexpensive, and fully standardised. By pulling on something, you will very quickly determine how the material will react to forces being applied in tension. As the material is being pulled, you will find its strength along with how much it will elongate and one of the more basic tests is to determine stress – strain relationships. [10] A simple uniaxial test consists of slowly pulling a sample of material in tension until it breaks. The major parameters that describe the stress-strain curve obtained during the tension test are the tensile strength (UTS), yield strength or yield point (σy), elastic modulus (E), percent elongation (∆L%) and the reduction in area (RA%). Toughness, Resilience, Poisson’s ratio (ν) can also be found by the use of this testing technique. 0.2 % off-set method is a commonly used method to determine the yield strength. Yield strength (σy) (0.2%) is found by drawing a parallel line to the elastic region and the point at which this line intersects with the stress-strain curve is set as the yielding point. [9] The following figure is the tensile tester that is used to test the
Sir Isaac Newton is the man well known for his discoveries around the term, Motion. He came up with three basic ideas, called Newton’s three laws of motion.
Here, we can use the vectors to use the Pythagorean Theorem, a2 + b2 = c2, to find the speed and angle of the object, which was used in previous equations.
Law of elasticity is known as Hooke’s law, showing the relationship between the forces applied to a spring and its elasticity, which states that relationship between small deformation of the object and the displacement or size are directly proportional to loading and the deforming force. According to Hooke’s law, elastic behaviour of solids could explain by the fact that in component ions, molecules, or atoms from normal positions, which is small deformation, are also proportional to the force that causes the displacement. The deforming force might be applied to a solid by squeezing, compressing, stretching twisting, or bending. Accordingly, spring will return to its primary size and shape upon discharge of the load (Tega, 2010).
The science of fluid mechanics is neither new nor biblical; however, most of the progress in this field was made in the 20th century. Therefore it is appropriate to open this text with a brief history of the discipline, with only a very few names mentioned.