110 likes | 252 Vues
This analysis explores the stress distribution in a tower structure using the method of joints. By focusing on joints A, B, and C, we derive equations for the forces acting on each joint, taking into account both X and Y directional forces. A free body diagram visualizes these forces, and we consider yield strength to evaluate the maximum force the tower can withstand. We calculate the stress based on the cross-sectional area of balsa wood, acknowledging factors that may cause discrepancies in our predictions, such as craftsmanship imperfections and unaccounted forces.
E N D
F0 The Method of Joints A B C Joint B F0 E F D FAB FCB +Y +X G H I FDB FFB FEB A Free Body Diagram K L J M N O FR
Joint B X Forces F0 +FAB -FCB +FDBX -FFBX = 0 FAB FCB Y Forces FDB FDBY -F0 +FEB +FDBY +FFBY FDB FFB FDBX FEB +Y = 0 +X
F0 15 Joints A B C 15 FX equations 15 FY equations E F D 30 Variables G H I A “system of equations” K L J Solution would required computer software M N O FR
Yield Strength The amount of stress a material can withstand before it begins to deform Values can differ for tension or compression Use the internet to find a value for the yield strength of balsa wood in compression
Cross Sectional Area Depth = 3mm Width = 4mm 12mm2 Area = 4mm * 3mm = ?
Maximum Force P = F / A Stress = Pressure = Force / Area Stress = Yield Strength Yield Strength * Area = Max Force
Total Force Our ‘max force’ only accounts for a single truss Must count all the trusses at a given height to get total force 1 2 3 4 5 1 2 3 Sided Tower 3 Total Force = Max Force * ? 5 * 3
Reasons our predictions may be off We only accounted for forces in the Y direction Considered trusses to only experience compression Calculations did not account for imperfect craftsmanship