Speed Rate (Stress Control) Calculation
2
Point 1 σ = 130 N/mm 2 , t = 6 s Stress rate, Ṙ = 130/ 6 = 21.66 N/mm 2 s -1 @ 21.66 MPas -1 Point 2 σ = 253 N/mm 2 , t = 11 s Stress rate, Ṙ = 253/ 11 = 23 N/mm 2 s -1 @ 23 MPas -1 Point 3 σ = 369 N/mm 2 , t = 15 s Stress rate, Ṙ = 369/ 15 = 24.60 N/mm 2 s -1 @ 24.60 MPas -1 Point 4 σ = 512 N/mm 2 , t = 40 s Stress rate, Ṙ = 512/ 40 = 12.80 N/mm 2 s -1 @ 12.80 MPas -1 6.005, 130.1734086 15.019, 368.9320782 40.004, 511.7589026 67.004, 489.2031558 -100 0 100 200 300 400 500 600 0 20 40 60 80 100 120 Stress, σ (N/mm 2 ) Time, t (s) (1) (3) (4) (5) 11.149, 253.4939215 (2) Stress vs Time CALCULATION OF STRESS RATE
-
Upload
hajijamali -
Category
Documents
-
view
228 -
download
3
description
-
Transcript of Speed Rate (Stress Control) Calculation
-
Point 1 = 130 N/mm2, t = 6 s Stress rate, = 130/ 6 = 21.66 N/mm2s-1 @ 21.66 MPas-1
Point 2 = 253 N/mm2, t = 11 s Stress rate, = 253/ 11 = 23 N/mm2s-1 @ 23 MPas-1
Point 3 = 369 N/mm2, t = 15 s Stress rate, = 369/ 15 = 24.60 N/mm2s-1 @ 24.60 MPas-1
Point 4 = 512 N/mm2, t = 40 s Stress rate, = 512/ 40 = 12.80 N/mm2s-1 @ 12.80 MPas-1
6.005, 130.1734086
15.019, 368.9320782
40.004, 511.7589026
67.004, 489.2031558
-100
0
100
200
300
400
500
600
0 20 40 60 80 100 120
Stress, (N/mm2)
Time, t (s)
(1)
(3)
(4) (5)
11.149, 253.4939215 (2)
Stress vs Time
CALCULATION OF STRESS RATE
-
Point 5
= 489 N/mm2, t = 67 s Stress rate, = 489/ 67 = 7.30 N/mm2s-1 @ 7.30 MPas-1
As refer to Table 3 in BS EN ISO 6892-1:2009; Modulus of Elasticity of the
material E
MPa
Stress Rate
MPas-1 Min. Max.
150 000 2 20 150 000 6 60
*Note:- 1 psi = 0.00689475729 MPa, 1 F = -17.2222 C
Estimation of modulus of elasticity for carbon steel, E = 30 millions psi/ 0.00689475729 MPa = 206, 843 MPa Thus, As refer to BS EN ISO 6892-1:2009, Clause 10.4.2.5 stated If the testing machine is not capable of measuring or controlling the strain rate, a crosshead separation rate equivalent to the stress rate given in Table 3 shall be used until completeion of yield. As refer to the Table 3; Stress rate () for carbon steel shall within 6 M MPas-1 to 60 MPas-1.
