Stress calculation of H-beam under self weight Ha ha, in fact, I'm rather confused now. I want to pursue the correct answer. Let me give you an example to see if it's correct? A 21 meter long H-beam with two ends simply supported, size 600 (H) * 200 (W) * 11 (web thickness) * 17 (flange thickness) In order to calculate the maximum normal stress under self weight, the self weight is simplified as uniform load q = 0.998n/mm, moment of inertia: 7.76 + E008 mm ^ 4, then the maximum bending moment M = QL ^ 2 / 8 = 55014750n * mm The maximum stress of the beam is σ = mi / y = 50014750 * 7.76e8/600 (beam height) = 35MPa Excuse me, is my calculation correct? Please have a look,

Stress calculation of H-beam under self weight Ha ha, in fact, I'm rather confused now. I want to pursue the correct answer. Let me give you an example to see if it's correct? A 21 meter long H-beam with two ends simply supported, size 600 (H) * 200 (W) * 11 (web thickness) * 17 (flange thickness) In order to calculate the maximum normal stress under self weight, the self weight is simplified as uniform load q = 0.998n/mm, moment of inertia: 7.76 + E008 mm ^ 4, then the maximum bending moment M = QL ^ 2 / 8 = 55014750n * mm The maximum stress of the beam is σ = mi / y = 50014750 * 7.76e8/600 (beam height) = 35MPa Excuse me, is my calculation correct? Please have a look,

The calculation is correct

Additional stress in soil mechanics
The width of a foundation is 4m, the length is 8m, and the additional stress of the base is 90kpa. If the vertical additional stress at 6m depth below the center line is 56.8kpa, the width of another foundation is 2m, the length is 4m, and the additional stress of the base is 100KPA. What is the additional stress at 6m depth below the corner?
The answer is 15.8?

The first step: the stress is equivalent to the concentrated load, foundation 1: P1 = 4m * 8m * 90kpa = 2880kn, foundation 2: P2 = 2m * 4m * 100KPA = 800KN
Step 2: by Boussinesq J: σ z = k * P / (Z * z)
Step 3: for foundation 1: σ Z (z = 6m) = 56.8kpa, P1 = 4m * 8m * 90kpa = 2880kn, z = 6m, then the value of K can be calculated by using the second step formula, k = 0.71
For foundation 2: σ Z (z = 6m) =? P2 = 2m * 4m * 100KPA = 800KN, k = 0.71, z = 6m, the value of σ Z (z = 6m) can be calculated by using the second step formula, σ Z (z = 6m) = 15.8kpa
I wonder if it will help you

Eight practical questions
The distance between the two places is 10 kilometers. First, a walks from a to B for an hour and a half. Then B rides a to B and arrives at the same time. The distance b travels per hour is two kilometers more than the distance b travels per hour

B: it's twice the distance every kilometer?
Let the velocity of a be x and the velocity of B be y
The time of B is 10 / y
y=2x+2;1.5x+10x/y=10
x=4;y=10
A: the speed of a is 4 km / h, and that of B is 10 km / h

Survey questions and application questions
A diversion channel will be excavated from point a on one side of a small mountain to point B on the other side. In engineering design, it is necessary to measure the distance between two points a and B. now select a point C where two points a and B can be seen at the same time, and measure AC = 140m, BC = 200m, ∠ ACB = 60 ° to find the distance between a and B

There are answers on page 113 of senior one's math book

Calculation of electronic measurement,
It is known that the deflection factor of oscillograph is 0.5v/div, the effective width of fluorescent screen is 8div, the scanning time factor is 0.2ms/div, the probe is × 10 attenuation, the measured signal is sine wave, the height of waveform displayed on fluorescent screen is 6div, the two measured signal waveforms occupy 10div in X direction. (1) calculate the period T, frequency f (2) calculate the amplitude um, effective value u?

Your description is not complete, but according to the conditions provided:
If the scanning factor is 0.2ms/div and there are 10 div in total, then the total scanning time is 0.2 × 10 = 2ms. This is the period of two signal waveforms, and the period of the signal is 1ms. The frequency is the reciprocal of the period, that is, 1 × 10 ^ 3Hz, which is 1kHz
If the vertical factor is 0.5v/div, the actual reading is 6div, and the ratio of the probe is × 10, the amplitude of the signal is 6 × 10 × 0.5 = 30V. The maximum value of the sine wave is twice the root of its RMS, that is, um = u × 2 ^ (1 / 2). Where: U - is the RMS, um - is the maximum value

A clothing factory is going to process 400 sets of sportswear. After 160 sets of sportswear are processed, new technology is adopted to improve the work efficiency by 20% compared with the original plan. As a result, it takes 18 days to complete the task. How many sets of sportswear are processed in the original plan?

Suppose that the original plan is to process x sets per day, from the meaning of the question: 160x + 400 − 160 (1 + 20%) x = 18. The solution is: x = 20. It is tested that x = 20 is the solution of the original equation. Answer: the original plan is to process 20 sets per day

A math problem in grade one of junior high school
Number of years in which Mr. Lin was born:
Plus five is a multiple of nine
Plus 6, it's a multiple of 10
Plus 7, it's a multiple of 11
Plus 8, it's a multiple of 12
It's best to use the equation

X + 5 = 9ax + 6 = 10bx + 7 = 11cx + 8 = 12dx-4 = 9 (A-1) = 10 (B-1) = 11 (C-1) = 12 (D-1) B = 9 / 10 (A-1 + 1C = 9 / 11 (A-1) + 1D = 9 / 12 (A-1) + 1 = 3 / 4 (A-1) + 1a-1 is the common multiple of 10,11,4, and the least common multiple is 220

A mathematical problem of one variable one degree equation in junior high school
There are two routes between a and B. a person rides a bicycle from a to B along route one at a speed of 9km / h, and then returns to a along route two from B at a speed of 8km / h. It is known that route two is 2km less than route one and takes one eighth of an hour less than route one. The length of route one can be calculated

The length of line one is x, and the length of line two is X-2
x/9-(x-2)/8=1/8
x=9km
OK, give me a score

How much does the sales volume of a product after 10% discount increase compared with that without discount?
0.9 + 0.9 * x = 1, x = 11.11% (what is the solution of this equation, please explain in words)

It can be said that:
First, he assumes that the unit price and sales volume of the original goods are all 1, according to the total sales volume = unit price of goods * sales volume = 1 * 1 = 1;
After the price reduction, the unit price of goods = 1 * (1-10%) = 0.9; the total sales volume = 1; assuming that the sales volume increased by X, then the current sales volume = 1 * (1 + x); so: 0.9 * 1 * (1 + x) = 0.9 + 0.9 * x = 1. The solution is: x = 11.11%

The concept of linear equation of one variable is as follows______ ．

The concept of one variable linear equation: the equation with an unknown number and the highest degree of the unknown number is one variable linear equation. So the answer is: the equation with an unknown number and the highest degree of the unknown number is one variable linear equation