Question

Learning Goal: To solve for forces in statically indeterminate bars with axial loads. Consider a new structure, where the thickness of the bar is reduced to 32.5 mm from C to B (it is still square) (Figure 2) and <= 3.75 m. If the applied load is F - 370 kN , then what is the reaction at ? Let a positive reaction act to the right. The total length is still 6 m Express your answer with appropriate units to three significant figures. View Available Hints) ? When the number of reaction forces is greater than the number of equilibrium equations, the system is statically indeterminate. Solving for the reactions requires some additional equations. These additional equations come from considering compatibility relationships (.e., continuity of displacements and relationships between displacements and loads). For an axially loaded member, the compatibility relationship for the deflections can be written by setting the total relative axial displacement between the ends of the member to a known value. NL The load-displacement relationship 8 - AE gives another equation for the deflections. Once the internal normal force of each segment is written in terms of the end reactions and applied loads, there is enough information to solve for the reactions. FE Value KN Submit Previous Answers X Incorrect; Try Again; 3 attempts remaining Part C-Load point for equal forces Consider the structure from Part B (Figure 2). What value of 2 will lead to equal reaction forces at A and B? Express your answer in meters to three significant figures. Figure 2 of 2 View Available Hint(s) IVO AEcIt vec c ?

Answer 1

son Cruien F = 370KN t = 65mm tz= 32.5mm B. 2 A = te = (63)²x10-3² m2 x = (65x1037 m2 CB - Tension the AC- Compression the) С Re C B -RA F-RA Az = t₂² (32-591033² m2 fo & Snet zo SAC +SCB=0 RAxx + (FRA) x (1-2) 0 AI E AL u= 3.75m - Ron 3.75 l=6m (65210-372 + (F-PA) & (6-3.75) = 0 (32.5x103) 2 RA = (2.4) (FRA) F-370KN. RA= 2.4 (370 -RA)

RA=261.176 KN Ans part ① equal reaction i RA= RB= [ 370 2 372 = 18 5KN e Sret zo -RA a + RB (2-x) AZ E ALE - 0 1 85xx + 8 185x (6- x) (32.5x 1032 = 0 (65x10-32 x=4.8m
plz comment if answer is wrong before down vote. And plz upvote if solution is helpful