Find attached pdf for 2 questions in the assignment and answer will be required to be in the excel sheet provided.
instructions Instructions Enter your name and student number (note pay particular attention to your student number as this is used to generate solutions for marking your values) Enter your results in the yellow cells provided in the "solutions" tab. Do not move the location of any of the yellow cells Use exact values where possible in calculation, and enter exact values in cells. It is recommended to use Microsoft Excel (or some other spreadsheet software) to process the calculation component of the results. Results are marked correct if within 5% tolerance of exact answer. Submit solutions online using Canvas - file is uploaded where this template file was downloaded from Each time a submission is uploaded this is an "attempt". Each attempt should have 1 file: this spreadsheet Multiple submission attempts are possible, but only the LAST submission attempt is marked Email or hard copy submission will not be accepted &"Calibri"&12&KEEDC00RMIT Classification: Trusted&1# solutions name student # Refer to the assignment for more detailed description of the parameters to be entered 1Question 1 (40%) a)Stiffener axial loads (lbf): Use positive for tension and negative for compression Segment (Seg) and location (Loc), e.g. AB A is the force in stiffener segment AB at location A SegLoc ABA B BCB C AFA F BDB D CEC E DED E DGD G EHE H FGF G GHG H Shear flows (lbf/in). Only absolute values marked (signs ignored) Panel and edge, e.g. ABGF AB is panel ABGF, edge AB ABGFAB BG GF FA BCEDBC CE ED DB DEHGDE EH HG GD (b)Stiffener areas (in2), for each segment AB BC AF BD CE DE DG EH FG GH Shear panel thicknesses (in) for each panel ABGF BCED DEHG 2Question 2 (60%) a)Shear flows (N/mm). Only absolute values marked (signs ignored) Panel, e.g. 1-2 is the panel between stiffeners 1 and 2 1-2 1-3 3-1 curved 3-4 2-5 2-4 5-4 Criitical margin of safety (MoS) MoS b)Resized panel thicknesses (mm) Panel, e.g. 1-2 is the panel between stiffeners 1 and 2 1-2 1-3 3-1 curved 3-4 2-5 2-4 5-4 Question 2a consequential marks Provide intermediate results to assist with awarding consequential marks Maximum of marks from either final values or consequential marks taken Panel, e.g. 1-2 is the panel between stiffeners 1 and 2, with positive direction from 1-2 "basic" Shear flows (N/mm), qb 1-2 1-3 3-1 curved 3-4 2-5 2-4 5-4 matrix terms A, B and x that could be used to solve for unknowns x using [A]{x} = [B], with qc positive clockwise and qb positive as stated above A11 A12 A13 A14 A21 A22 A23 A24 A31 A32 A33 A34 A41 A42 A43 A44 B11 B21 B31 B41 x11 x21 x31 x41 Margin of Safety (MoS) in shear 1-2 1-3 3-1 curved 3-4 2-5 2-4 5-4 &"Calibri"&12&KEEDC00RMIT Classification: Trusted&1# Microsoft Word - AERO2359-2110_assignment-2.docx Page 1 of 3 Aerospace Structures Assignment 2: Stiffened Structures Individual assignment: One per student. Multiple attempts allowed, but only last submission graded. Ensure you review your file after submission and avoid leaving submission until the last minute. Marks awarded for ANSWERS only. Use solutions template to enter in results and follow instructions provided in template file. Question 0: Your student number is used to assign parameters, according to the table below. Digit 3rd 4th 5th 6th 7th Parameter a b A B C D E F Value 0 0.90 0.90 12 150 5 20 2 10 1 0.91 0.91 12.1 151 5.1 21 2.1 11 2 0.92 0.92 12.2 152 5.2 22 2.2 12 3 0.93 0.93 12.3 153 5.3 23 2.3 13 4 0.94 0.94 12.4 154 5.4 24 2.4 14 5 0.95 0.95 12.5 155 5.5 25 2.5 15 6 0.96 0.96 12.6 156 5.6 26 2.6 16 7 0.97 0.97 12.7 157 5.7 27 2.7 17 8 0.98 0.98 12.8 158 5.8 28 2.8 18 9 0.99 0.99 12.9 159 5.9 29 2.9 19 e.g.: Student number 3308705, produces the following table of values Digit 3rd 4th 5th 6th 7th Parameter a b A B C D E F Value 0 8 7 0 5 0 0.9 0.98 12.7 157 5 20 2.5 15 Scott Loh Highlight Scott Loh Highlight Scott Loh Highlight Scott Loh Highlight Page 2 of 3 Question 1 (40%) The tapered stiffened beam below is loaded by forces as shown. The beam is assumed to consist of stiffeners carrying only direct stress and shear panels carrying only shear stress. The material used has E = 10500 ksi, G = 3900 ksi, ty = 48 ksi,cy = 38 ksi, sy = 37 ksi. The values of a, b, A, C, E are taken from Question 0. (a) Calculate the stiffener axial loads (lbf) at the end of each beam segment and the shear flows (lbf/in) along each panel edge. (30%) (b) Size the beam by determining stiffener areas (in2) and shear panel thicknesses (in). (10%) For stiffeners, size to yield stress (in tension or compression), considering the maximum load in each segment (i.e. each segment can have a different area). For the shear panels, size to yield stress (in shear, maximum in each panel) or shear buckling, whichever is critical. For the buckling calculation, assume that the shear panels are simply supported on all edges, and for the tapered panels use the smaller edge dimensions (i.e. assume a rectangular panel with the smaller of the width and height edge dimensions). When sizing, use a minimum possible area of 0.30 in2 and a minimum possible thickness of 0.0052 in. A B F G C H D E dimensions in inches S1 5.0 5a 6.0 S3 2.5b 6a S2 y x S1 = A kip S2 = C kip S3 = E kip 2b Page 3 of 3 Question 2 (60%) The three-cell structure shown below uses stiffeners connected with shear panels. Note that the curved panel between stiffeners 1 and 3 is semi-circular. The structure is under the action of forces and moments as shown. Assume the shear panels do not carry any direct stress. The material properties are: E = 72 GPa, G = 28 GPa, ty = 270 MPa, cy = 240 MPa, y = 170 MPa. The values of a, b, B, D, F are taken from Question 0. (a) Calculate the shear flow (N/mm) in each panel and determine the critical margin of safety in shear (not buckling or any other mode). (50%) (b) Re-size the thickness (mm) of the shear panels to reduce the cross-sectional area to achieve the following design requirements (10%): 1. area fraction A/A0 less than 0.30 2. all margins of safety greater than or equal to 0.0 3. no panel thickness less than 0.2015 mm The area fraction is calculated as A/A0, where A is the cross-sectional area of all panels combined, and A0 is the cross-sectional area of all panels using thicknesses as shown in the figure below. In re-sizing the panels, you should consider that the beam cross-section dimensions and stiffener areas are fixed, and that only the panel thicknesses can be varied. You should only consider failure due to shear (not buckling or any other mode). dimensions in mm areas in mm2 Booms 2, 4, 5: area = 50b panel thickness (t) t = 1.5 mm for all panels except t1-3 = 5 mm y x Booms 1, 3: area = 700a L = B kN D = D kN MAC = F kN m 0.5D 0.5D MAC 1 4 2 3 1500 I II III 750 5 200 0.3L MTE MTE = 0.2F kN m 0.7L