5) A free body diagram of a structure illustrates all of the components of a structure...

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5) A free body diagram of a structure illustrates all of the components of a structure in isolation and is used to document all of forces acting on each structural component, including the reactions between components. The diagram is used to trace the path and magnitude of loads applied to the structure. a) A four-axle railcar of gross rail load W is supported by two trucks. Using the diagram on the following page as a guide, draw a neat free body diagram to illustrate the path of the railcar vertical load from the center plate at one end of the railcar down through the truck to the contact patch on the top of the rail. Label the magnitude of the forces as a fraction of W acting on the following structural components of the railcar: Axle journal and wheelset Bearing adapter Center bowl and truck bolster Center plate on bottom of carbody JOURNAL WHEELS ov AXLE ROLLER BEARING ADAPTERS ROLLER BEARINGS SIDEFRAME CAR BODY CENTER PLATE CENTER BOWL Roller bearing assembly Sideframe TRUCK BOLSTER SPRING GROUP (Located Here) Spring group Wheel/rail contact patch WHEELSET SIDEFRAME b) As discussed in lecture, the size of the wheel/rail contact patch is roughly the same size as a dime. The diameter of a dime is 0.705 inches. If the railcar in part (a) has a gross rail load of 286,000 pounds, what is the average stress in psi at the wheel/rail contact patch? c) The typical yield stress of structural steel is 36,000 psi. How does your answer in part (b) compare to this yield stress? What does this tell you about how the steel used to manufacture railway wheels compares to that of rails? 5) A free body diagram of a structure illustrates all of the components of a structure in isolation and is used to document all of forces acting on each structural component, including the reactions between components. The diagram is used to trace the path and magnitude of loads applied to the structure. a) A four-axle railcar of gross rail load W is supported by two trucks. Using the diagram on the following page as a guide, draw a neat free body diagram to illustrate the path of the railcar vertical load from the center plate at one end of the railcar down through the truck to the contact patch on the top of the rail. Label the magnitude of the forces as a fraction of W acting on the following structural components of the railcar: Axle journal and wheelset Bearing adapter Center bowl and truck bolster Center plate on bottom of carbody JOURNAL WHEELS ov AXLE ROLLER BEARING ADAPTERS ROLLER BEARINGS SIDEFRAME CAR BODY CENTER PLATE CENTER BOWL Roller bearing assembly Sideframe TRUCK BOLSTER SPRING GROUP (Located Here) Spring group Wheel/rail contact patch WHEELSET SIDEFRAME b) As discussed in lecture, the size of the wheel/rail contact patch is roughly the same size as a dime. The diameter of a dime is 0.705 inches. If the railcar in part (a) has a gross rail load of 286,000 pounds, what is the average stress in psi at the wheel/rail contact patch? c) The typical yield stress of structural steel is 36,000 psi. How does your answer in part (b) compare to this yield stress? What does this tell you about how the steel used to manufacture railway wheels compares to that of rails?