PRASANNNAN DURAIRAJ

Types of Supports In the  structures , supports refer to the part of the structure which may help other parts to resist loads. Columns, walls, and foundations are the obvious support systems in an architectural structure. In addition, a beam can support another beam. To simplify the understanding of the support actions, we generally divide them into three types: Roller Support : This is the type of support which only restrains the structure from moving in one or two perpendicular directions. However, the structure can move in the other directions and it can also rotate. The joint that is supported by a roller support has four or five degrees of freedom. If the structure acts as a two-dimensional system, the roller support restrains the node form moving in one direction only. In general, there is a support reaction (force acting from the support to the structure) in the direction of the restrained  degree of freedom . Therefore, roller supports have one or two support reactions. Roller

  THE 7 ESSENTIAL ELEMENTS THAT MAKE YOUR BUILDING SUSTAINABLE For all our self builder customers from those building new from scratch to those who are refurbishing or upgrading this is the time to incorporate sustainability into your project by design and through the careful choice of materials, getting this right now will insulate you against spiraling energy bills and running costs and provide a durable long lasting healthy home. Most self builders are creating buildings to last long after they have gone and are often keen to explore proven (often traditional based) and beneficial building systems that would not necessarily be offered by a developer or volume house builder. So what’s involved in building green? 1. Use enough insulation   - most buildings are built with too little Simply stated, the more insulation you incorporate into the structural elements of your home (such as the walls, roof and floor), the more heat it will retain and the more efficient it will be in use, don’t

CERAMICS PROPERTIES AND PROCESSING The properties of ceramic materials, like all materials, are dictated by the types of atoms present, the types of bonding between the atoms, and the way the atoms are packed together. This is known as the atomic scale structure. Most ceramics are made up of two or more elements. This is called a compound. For example, alumina (Al 2 O 3 ), is a compound made up of aluminum atoms and oxygen atoms. The atoms in ceramic materials are held together by a chemical bond. The two most common chemical bonds for ceramic materials are covalent and ionic. For metals, the chemical bond is called the metallic bond. The bonding of atoms together is much stronger in covalent and ionic bonding than in metallic. That is why, generally speaking, metals are ductile and ceramics are brittle. Due to ceramic materials wide range of properties, they are used for a multitude of applications. In general, most ceramics are: hard, wear-resistant, brittle, refractory, thermal insu

Fracture is the separation of a material into two or more pieces under the action of an applied  stress . A material may undergo one of two major types of fracture modes depending on its mechanical properties: ductile and brittle. Materials undergoing   ductile fracture   first experience   plastic deformation , i.e., the material resists the fracture by stretching itself. Imagine pulling on two ends of a plastic bag. The bag stretches by a considerable amount before it eventually tears. This plastic deformation, which is not limited to   polymers , is also seen in   metal alloys .   Materials that undergo  brittle fracture , on the other hand, will fracture with negligible plastic deformation. In other words, they break without warning. Regardless of the type of fracture, during failure a material will experience: Crack formation , where all fractures start, and Propagation of the crack , in response to the applied stress In ductile fractures, this crack is stable, i.e., it will under

ELASTIC AND PLASTIC DEFORMATION Figure 1. A spring wire is an example of elasticity, since it returns to its original shape, after being pulled and pushed on. Objects deform when pushed, pulled, and twisted.  Elasticity  is the measure of the amount that the object can return to its original shape after these external  forces  and  pressures  stop. This is what allows springs to store  elastic potential energy . The opposite of elasticity is  plasticity ; when something is stretched, and it stays stretched, the material is said to be plastic. When energy goes into changing the shape of some material and it stays changed, that is said to be plastic deformation. When the material goes back to its original form, that's elastic deformation.  Mechanical energy  is lost whenever an object undergoes plastic deformation. Manufacturing goods from raw materials involves a great deal of plastic deformation. For example, rolling steel into a particular shape (like rebar for construction) invol