Power-Driving Engineering CAE - Assignment Example

Name: Course: Instructor: Date: Mechanical Engineering (Elevator) The choice and proper estimation of safety factors is a vital step in all design procedures. Historically safety factors used to be a number by which the designer scales down the ultimate strength of the material to produce a “working or design strength”. Design calculations and material testing procedures used to be quite simplified and as a result designers used to use very high safety factors (in some cases as high as 30-40). Advances in stress analysis, CAE, material testing and experimental techniques have facilitated much more accurate data and analysis procedures at the fingertips of designers. Accordingly, a more rigorous definition of safety factors and stricter estimates have developed and are commonly practiced in various types of designs. Safety factor (SF) is also defined as the Factor of Safety (FoS), which is a term used to describe the capacity of a system beyond the actual or expected loads. Determining the safety factor is important such as bridges and buildings to present the accuracy of a reasonable carry load. That is; the safety factor determines the additional weight that a structure can carry beyond the accurate load it can carry. The safety factor is attained through the calculation method of, SF = the strength of the component/ load of the component. Some of the important factors affecting the estimate of a good and proper safety factor are discussed below. Material quality The quality of the available material is determined by placing a portion of the material under several experiments to determine the accuracy or safety factor of the material. The values of the strength of materials are the quartile that relates on a prospect of a 0.05. That is; it is the compressive power of tangible and compressive/ malleable load of the steels. The benefits that are used to determine the strength and quality of the material are based on the lower and upper prospects. The primary values present the prospect of 0.95 while the second values probability is 0.05 (Ch. 4, 1). The values are approved in alternation dependent on the sway of the issue. The load of the material is vital to the design and safety factor (Fos, 3). It includes outlining the fatigue properties of the materials. To reach the design value of material properties, the typical values are allocated using the restricted safety factor. The properties of the material have to be identified in aspect for safety factor including the identification of the operating settings (Fos, 3). Workmanship is also used as an assumption for determining the quality of the product. That is; if the supplier of the product is reputable, the safety factor of the product can easily be attained using the code of practice of the vendor. Murphy, (291) presents that if the material disaster can damage the personnel or hurt the equipment’s in a thoughtful technique; the F value used for the safety factor must be high. F is apparent as the value of factor of safety. The value of F on materials is accomplished when the material is tested before it is used and when it is in use. Thus, when testing the materials in laboratories, it is vital to be applied to identify the specimen (material been tested) figures, which are enhanced than the actual parts when under construction. The accuracy of material/ content data and inspection and maintenance procedures for material defects also determine the safety factor of the material used (Fos, 3). The documentations of the material have to be attained by confirming regular maintenance and inspection of the materials. Load Factor The accuracy of load determination articulates attaining the safety factor of the load. To certify the safety factor of the load factor, one must regulate the accuracy of the load. The accuracy is guaranteed by ensuring the load is applied to each load cell in the contemplating system to evade any strain measures in the cell. The process may send comparative signal alterations to the twisting as a substitute of the weight of the load/ material. The cells of the load must be measured to define correct weighing while using malleable connections to ensure the weight of the load is not supported by anything else. Consequently, the accurate weight of the load is attained. Control of the applied load is attained through certifying the safety factor of the material. The cell load should correctly be aligned by ensuring each cell and its increasing hardware load directly. Additionally, the floor or edifice below the load cells should be strong to bear the fillings and vessels of the weight among other equipment on the structure. Thus, the point load level should regularly be at +/- 0.5percent from zero to full load to dodge any undesirable side loads on the load cells that can weaken the correctness of the balancing systems. Therefore, for accurate balancing, the load cells must upkeep the whole weight been measured (Chapter 2, 10). A pressure discrepancy can lead to weighing faults that lead to unwelcome forces to the weighing systems. Nature of the load also influences the safety level or value of the factor. The nature of the load is reliant on other features such as the trembling when the structure is being used among others such as temperatures. Other load factors govern the performance of the objective level, determining the consistency index, type, and measurements for each load and the assessment of the load and resistance factors. The factors outline the conception of load resistance factors. The nominal resistance value is defined as the Rn, which certifies the satisfaction of the target readability index. The nominal conflict value, the endless mean value, joint prospect density function resistance R and load affect S, FRS (r, s) are influenced through regulating the parallel direction (Chapter 2, 11). The direction confines the state prospect, which is volume denoted as FRS (r, s) in the sphere where (r –s Read More