A production line is an important class of manufacturing system when large quantities of identical or similar products are to be produced. The performance of a production line is highly influenced by machine failures. When a machine fails, it is then be unavailable during a certain amount of time required to repair it. Analysis of production lines divides into three types: analytical, approximation and simulation models. The analytical and approximation models have assumptions which make these models unrealistic such as reliable workstations, certain processing distribution, the first workstation cannot be starved and the last workstation cannot be blocked. The main problems in production lines treatment are the calculation of throughput and average levels of buffers because of the great size of state space. An analytical model is reviewed to clarify the limitations to use such treatment in real production lines. Simulation modeling of production lines is considered very important for designers interested in: Workload Allocation Problem (WAP), Server Allocation Problem (SAP), and Buffer Allocation Problem (BAP). This paper studies and analyzes the performance keys, which effect on production lines. A simulation model is developed by using ARENA software and used to analyze and test several bottlenecks that are causing severe congestions in different areas on the production line and could resolve all of these bottlenecks. In this paper, an actual cement production line is studied. After a simulation time of 13 days, a simulation results show the line bottlenecks, workstations utilization, buffer capacities and the line production rate. The outputs clarify redesign of allocation of buffers, which verify an optimum size could be made; it might be taken into consideration when designers implement such lines. Finally modified better workstations utilization, buffer capacities and the line production rate with an increase about 15% of the production rate and economizing of 37 % from buffer capacities

A production line is an important class of manufacturing system when large quantities of identical or similar products are to be produced. The performance of a production line is highly influenced by machine failures. When a machine fails, it is then be unavailable during a certain amount of time required to repair it. Analysis of production lines divides into three types: analytical, approximation and simulation models. The analytical and approximation models have assumptions which make these models unrealistic such as reliable workstations, certain processing distribution, the first workstation cannot be starved and the last workstation cannot be blocked. The main problems in production lines treatment are the calculation of throughput and average levels of buffers because of the great size of state space. An analytical model is reviewed to clarify the limitations to use such treatment in real production lines. Simulation modeling of production lines is considered very important for designers interested in: Workload Allocation Problem (WAP), Server Allocation Problem (SAP), and Buffer Allocation Problem (BAP). This paper studies and analyzes the performance keys, which effect on production lines. A simulation model is developed by using ARENA software and used to analyze and test several bottlenecks that are causing severe congestions in different areas on the production line and could resolve all of these bottlenecks. In this paper, an actual cement production line is studied. After a simulation time of 13 days, a simulation results show the line bottlenecks, workstations utilization, buffer capacities and the line production rate. The outputs clarify redesign of allocation of buffers, which verify an optimum size could be made; it might be taken into consideration when designers implement such lines. Finally modified better workstations utilization, buffer capacities and the line production rate with an increase about 15% of the production rate and economizing of 37 % from buffer capacities

A production line is an important class of manufacturing system when large quantities of identical or similar products are to be produced. The performance of a production line is highly influenced by machine failures. When a machine fails, it is then be unavailable during a certain amount of time required to repair it. Analysis of production lines divides into three types: analytical, approximation and simulation models. The analytical and approximation models have assumptions which make these models unrealistic such as reliable workstations, certain processing distribution, the first workstation cannot be starved and the last workstation cannot be blocked. The main problems in production lines treatment are the calculation of throughput and average levels of buffers because of the great size of state space. An analytical model is reviewed to clarify the limitations to use such treatment in real production lines. Simulation modeling of production lines is considered very important for designers interested in: Workload Allocation Problem (WAP), Server Allocation Problem (SAP), and Buffer Allocation Problem (BAP). This paper studies and analyzes the performance keys, which effect on production lines. A simulation model is developed by using ARENA software and used to analyze and test several bottlenecks that are causing severe congestions in different areas on the production line and could resolve all of these bottlenecks. In this paper, an actual cement production line is studied. After a simulation time of 13 days, a simulation results show the line bottlenecks, workstations utilization, buffer capacities and the line production rate. The outputs clarify redesign of allocation of buffers, which verify an optimum size could be made; it might be taken into consideration when designers implement such lines. Finally modified better workstations utilization, buffer capacities and the line production rate with an increase about 15% of the production rate and economizing of 37 % from buffer capacities

SOME PARAMETERS AFFECTING THE STATIC BEHAVIOR OF NORMAL STRENGTH RECTANGULAR R.C. SHORT COLUMNS CONFINED BY CFRP

SOME PARAMETERS AFFECTING THE STATIC BEHAVIOR OF NORMAL STRENGTH RECTANGULAR R.C. SHORT COLUMNS CONFINED BY CFRP

This paper describes a theoretical study of the effect of both acting axial loads and grade of concrete on the static behaviour of (32) thirty two Reinforced Concrete (RC) Beam-column joints. ABAQUS\CAE version 6.7, a nonlinear finite element analysis software package, was developed specifically for the analysis of reinforced concrete structures under plane stress conditions. Variable axial loads were applied and increased gradually with constant lateral load, which was applied maintaining at the top of the column at internal and external beam-column joint only the ultimate and cracking axial loads were recorded as well as the corresponding versus vertical displacement, the maximum joint shear stresses, axial, stresses strains, and absorbed energy, mode of failure using different grades of concrete C250, C400, C600 and C1200 were evaluated and recorded.

This paper describes a theoretical study of the effect of both acting axial loads and grade of concrete on the static behaviour of (32) thirty two Reinforced Concrete (RC) Beam-column joints. ABAQUS\CAE version 6.7, a nonlinear finite element analysis software package, was developed specifically for the analysis of reinforced concrete structures under plane stress conditions. Variable axial loads were applied and increased gradually with constant lateral load, which was applied maintaining at the top of the column at internal and external beam-column joint only the ultimate and cracking axial loads were recorded as well as the corresponding versus vertical displacement, the maximum joint shear stresses, axial, stresses strains, and absorbed energy, mode of failure using different grades of concrete C250, C400, C600 and C1200 were evaluated and recorded.

The behavior of the strip footing on sand was deeply studied in many publications. They were trying to improve this behavior through many techniques. These improvements include the using of geogrid and geotextile reinforcement, skirts on the sides of the footing to elongate the contact surface of the footing with soil. None of these studies had implemented in the effect of the contact shape of the footing on its behavior. In this present experimental study, it is intended to observe the behavior of the convex strip footing on sand with different strip footing contact shapes. A series of experiments using different convex strip footing contact shapes, are carried out on sandy soil. The results showed that the increase in the strip footing contact areas, did not increase the bearing capacity, but decreases the ultimate bearing capacity load from about 30% to 60%. Also with sever convex curve, the ultimate load decreases seriously.

Rock mass classification systems consider one of the design tools, which are used in conjunction with engineering assessments and other design approaches. There are many classification systems, which are widely employed in rock engineering. In this study one of these systems is used for the selection of the optimum panel width in phosphate mine Abu Tartur area. Geological Strength Index (GSI) is one of these systems which enables for calculations of the panel width. Data for the GSI system are obtained from geological reports, some field measurements and laboratory tests. The obtained panel width (wall length) for Abu-Tartur area is calculated to be about 100m (102m) which differs strongly from the applied length in the area (150m). So, it is recommended to apply this obtained length to secure safe mining conditions without roof falls which is the main problem facing underground mining in this area.

Rock mass classification systems consider one of the design tools, which are used in conjunction with engineering assessments and other design approaches. There are many classification systems, which are widely employed in rock engineering. In this study one of these systems is used for the selection of the optimum panel width in phosphate mine Abu Tartur area. Geological Strength Index (GSI) is one of these systems which enables for calculations of the panel width. Data for the GSI system are obtained from geological reports, some field measurements and laboratory tests. The obtained panel width (wall length) for Abu-Tartur area is calculated to be about 100m (102m) which differs strongly from the applied length in the area (150m). So, it is recommended to apply this obtained length to secure safe mining conditions without roof falls which is the main problem facing underground mining in this area.