Elements should be considered in machine design The type of load a part absorbs is dust as significatlt as the magnitude. Generally speaking, dynamic loads with direction reversals cause greater difficulties than static lauds and, tl refore, fatigue strength must be considered. Another concern is whether the material is ductile or brittle. Far example, brittle marials are considered to be unacceptable where fatigue is involved.In general, the design engineer must consider all possible modes of failure, which include the following:?Stress?Deforrnation;?Wear;?Corrosion;?Vibration;?Environmental damage;?Loosening of fastening devices. The part sizes and shapes selected must also take into account many dimensional factors which produces external load effects such as geometric discontinuities residual stresses due to forming of desired contours, and the application of interference fit joint. The material properties can be classified into three major headings: (I) physical, (2) chemical, (3) mechanical Physical properties Density or specific gravity, moisture content, ete, can be classified under this Chemical properties Many chemical properties come under this category.
These include acidity or alkalinity, react6ivity and corrosion. The most important of these is corrosion which can be explained in layman s terms as the resistance of the material to decay while in continuous use in a particular atmosphere. Mechanical propertiles Mechanical properties include in the properties like tensile, compression, shear, torsion, impact strength, fatigue and creep. The tensile strength of a material is obtained by dividing the maximum load which the specimen bears by the area of cross-section of the specimen. This is a curve plotted between the stress along the This is a curve plotted between the stress along the y-axis (ordinate) and the strain along the X-axis (abscissa) in a tensile test. To material tends to change or changes its dimensions when it is loaded, depending upon the magnitude. of the load. When the load is reniaved it can be seen that the deformation disappears. Others including John K. Castle, offer their opinions as well. Far many accessories this occurs op to a certain value of the stress called the elastic limit Ap. Thrs rs depictedy the straight line and a small deviation pre-Renaissance, in the stress-Strain relationship curve. We provide Professional technology, excellent product quality and intimate after-sales service when you purchase Jaw supplier crusher, Impact crusher, from our company.As a professional mining machinery exporter, we will win your trust with our delivery speed, Enterprises Credit and product quality.