PROJECT-1 (Spring 2016) MECH 5390/6390/6396 Fundamentals of the Finite Element Method Due Date: April 5, 2016 (Professor Lall) INSTRUCTIONS 1. Write a report with the result of the problems below. 2. Submit your report as a WORD (.doc) file via CANVAS. 3. Turn-in a hard-copy of your report in class. 4. Screen captures indicated in the questions below are a minimum requirement. Document your model results with screen captures where necessary. QUESTION‐1: DESIGN OF STABILITY‐BOOM A retractable stability-boom called the “outrigger”, is attached to the back of a heavy-lift truck and is designed to provide stability for lifting heavy off-centered loads. Figure 1 shows the stabilityboom attached to the back of a truck in its retracted position. Figure 2 shows the stability boom fully extended and engaged for an off-center lift. Figure 1: Retractable Stability-Boom attached to back of a Truck. (Courtesy of Miller Industries) Figure 2: Retractable Stability-Boom in Fully-Extended and Engaged Configuration. (Courtesy of Miller Industries) Given that the stability-boom is a 3-stage telescopic arm as shown in Figure 2, made of structural A-36 steel with the Elastic Modulus, E = 200 GPa, Poisson’s Ratio, = 0.33, and yield strength, ys = 250 MPa. Assume that the 2-largest telescopic stages are rectangular-tubular in x-section and the final stage is a rectangular tube with closed end (Figure 2). The stability boom is 1-meter long in its retracted position and 2-meter long in the fully extended configuration. Assume that each of the 3-telescopic stages have equal exposed lengths in the fully extended configuration. The truck is designed for a load capacity of 35,675 kg on the free-tip of the stability boom. Determine the x-section dimensions of the stability boom using the following steps: (a) Develop a Conceptual-Model for the fully-extended configuration of the stability-boom. Identify any assumptions, constraints, and boundary conditions. Justify why they are reasonable, and why the conceptual-model of the physical structure will represent the structure accurately. (b) Based on the Conceptual-Model in Part (a), develop a Finite-Element Model of the stability boom using (i) BEAM Elements (ii) Solid Elements. Initially assume the cross-section dimensions. Show screen-shots of your meshed-model with dimensions, boundary conditions, and loads. (c) Determine the required section dimensions for the stability-boom iteratively starting from your initial guess in Part (b), using both the BEAM model and the Solid Model? Assume a Factor-of-Safety of 2 at maximum load. Show all the cases analyzed. Clearly list any section-properties used. (d) Determine the free-end deflection at maximum load? Show the deformed and undeformed configuration of the stability-boom. (e) Show the contour plot of the von-mises stress, and the longitudinal normal-stress along the length. Identify the location of maximum stress in the stability boom? (f) Using your finite element model, show if a higher load capacity can be attained using an alternate cross-section of the stability boom? Show all the sections analyzed. QUESTION‐2 Determine the (a) deflections at points D and F and (b) axial stresses and forces in the structural members using two methods: (a) Using ANSYS Modeling and Post-Processing. Provide justification for the choice of the element used in the analysis. (b) Using hand-calculations using the stiffness matrix of the BAR element. (c) Evaluate the correlation between the FE results and the hand calculations. (d) Explain any differences between the FE model and the hand calculations.