Calculation basis of axial force envelope diagram
Publish: 2021-05-07 02:02:39
1.
The internal force under the action of dead load is combined with the internal force under the disadvantageous arrangement of various live loads
2. Under the action of moving load, the maximum value of the same kind of internal force of each section of the structure is expressed with a vertical bar according to a certain scale, and the figure obtained is the internal force envelope diagram
envelope graphs include m-envelope graph and q-envelope graph.
envelope graphs include m-envelope graph and q-envelope graph.
3. When designing load-bearing structures (such as crane beams, floor continuous beams and bridge structures), it is necessary to calculate the maximum and minimum internal forces (maximum negative value) of each section. The graph connecting the maximum and minimum internal forces of each section is called internal force envelope graph
technical terms of Civil Engineering:
the internal forces under the action of dead load and the internal forces under the unfavorable arrangement of various live loads are respectively combined to obtain the internal forces of each combination, and the internal forces of the combination are drawn on the same line and a baseline together, then the "internal force superposition diagram" is obtained, and its outer envelope line becomes the "internal force envelope diagram"
difference: under the action of external force, the internal forces of the structure are calculated, Internal force will be generated. Usually, the internal force changes with the position of the section to draw a graph. This kind of graph is called internal force graph. Generally, there are three kinds of Construction: shear force graph, bending moment graph and axial diagram. This is the basis of reinforcement
the influence line is the influence of the unit moving load on a certain value. By using the superposition principle, the influence of other loads can be calculated
if the internal force diagram mainly studies the effect of fixed or static load on the structure, then the influence line is to study the internal force change and calculation of the structure under the action of moving load, which is the difference.
technical terms of Civil Engineering:
the internal forces under the action of dead load and the internal forces under the unfavorable arrangement of various live loads are respectively combined to obtain the internal forces of each combination, and the internal forces of the combination are drawn on the same line and a baseline together, then the "internal force superposition diagram" is obtained, and its outer envelope line becomes the "internal force envelope diagram"
difference: under the action of external force, the internal forces of the structure are calculated, Internal force will be generated. Usually, the internal force changes with the position of the section to draw a graph. This kind of graph is called internal force graph. Generally, there are three kinds of Construction: shear force graph, bending moment graph and axial diagram. This is the basis of reinforcement
the influence line is the influence of the unit moving load on a certain value. By using the superposition principle, the influence of other loads can be calculated
if the internal force diagram mainly studies the effect of fixed or static load on the structure, then the influence line is to study the internal force change and calculation of the structure under the action of moving load, which is the difference.
4. (1) . bending moment envelope diagram
draw the bending moment envelope diagram of each component basic combination, unit: kn. M
for column members, the program only records the internal forces of the upper and lower sections of the column, and the moment envelope between the sections is connected by a straight line. Therefore, the moment envelope of the column may have a sudden inflection point. As long as the recorded section contains the most unfavorable section, it will not affect the checking results; The internal forces of 13 sections are recorded, and the envelope diagram is relatively smooth
(2) axial force envelope diagram
draw the axial force envelope diagram of each component basic combination, unit: kn< (3) shear envelope diagram
draw the shear envelope diagram of the basic combination of each component, unit: kn.
draw the bending moment envelope diagram of each component basic combination, unit: kn. M
for column members, the program only records the internal forces of the upper and lower sections of the column, and the moment envelope between the sections is connected by a straight line. Therefore, the moment envelope of the column may have a sudden inflection point. As long as the recorded section contains the most unfavorable section, it will not affect the checking results; The internal forces of 13 sections are recorded, and the envelope diagram is relatively smooth
(2) axial force envelope diagram
draw the axial force envelope diagram of each component basic combination, unit: kn< (3) shear envelope diagram
draw the shear envelope diagram of the basic combination of each component, unit: kn.
5. For example, in the lower right corner, each sequence from top to bottom represents the axial force, shear force and bending moment of the column. The left side of the yellow line represents the column internal force under the right earthquake condition, and the right side of the yellow line represents the column internal force under the left earthquake condition,
I hope it can help you
I hope it can help you
6.
When designing load-bearing structures (such as crane beams, floor continuous beams and bridge structures), it is necessary to calculate the maximum and minimum internal forces (maximum negative value) of each section. The graph connecting the maximum and minimum internal forces of each section is called internal force envelope graph
the effect of dead load and moving load (live load) should be considered in the internal force envelope diagram in practical work, and the dynamic effect of moving load should also be considered. The specific method is to superimpose the internal force generated by the moving load after considering the dynamic effect and the internal force under the dead load according to the maximum and minimum internal forces that may occur, and draw the internal force envelope diagram according to the maximum and minimum internal forces of each section after superimposing
7. http://jpkc.yrcti.e.cn/lx/jxfaysd/wjzhlx/jz.htm
I. calculation principle of bending moment envelope diagram program of simply supported beam:
the internal force envelope diagram of beam is a graph reflecting the maximum internal force of each section of the whole beam under various possible loads. For the statically determinate simply supported beam bearing row and column loads, the beam is divided into several equal parts in the calculation. The maximum internal force of each equal section can be calculated by the most unfavorable load position method introced in the textbook. The calculation method of the maximum internal force of all sections is the same, and the more the equal sections are, the more accurate the internal force envelope diagram will be<
2. Name of main identifier:
3. Calculation example:
1. As shown in Figure 1, the simply supported beam bears four moving loads. Try to use the source program to calculate and draw its internal force envelope diagram
2. Data preparation: as can be seen from Figure 1,
beam span --- 12m
number of equal beam segments --- take 10 parts of concentrated force --- 4
array of force values from left to right --- 82kn, 82kn, 82kn
array of force spacing from left to right --- 3.5m, 1.5m, 3.5m
3 Calculation of internal force and drawing of internal force diagram
the calculation program of bending moment envelope diagram of simply supported beam written by visual basic can be directly run in Windows 98 environment after transforming into exe file. Click this application to pop up a calculation window, as shown in Figure 2. After inputting data, press the calculation button to get the maximum bending moment value of equal section
Fig. 2
according to the calculated results, the envelope diagram of internal force diagram of continuous beam can be drawn
example 2: a highway bridge bears the load of class 15 motorcade in the code for design of highway bridges, as shown in Figure 3. Try to use the source program to calculate and draw its internal force envelope diagram The motorcade can enter the bridge from left or right, and select two ways to enter the bridge for calculation.
I. calculation principle of bending moment envelope diagram program of simply supported beam:
the internal force envelope diagram of beam is a graph reflecting the maximum internal force of each section of the whole beam under various possible loads. For the statically determinate simply supported beam bearing row and column loads, the beam is divided into several equal parts in the calculation. The maximum internal force of each equal section can be calculated by the most unfavorable load position method introced in the textbook. The calculation method of the maximum internal force of all sections is the same, and the more the equal sections are, the more accurate the internal force envelope diagram will be<
2. Name of main identifier:
3. Calculation example:
1. As shown in Figure 1, the simply supported beam bears four moving loads. Try to use the source program to calculate and draw its internal force envelope diagram
2. Data preparation: as can be seen from Figure 1,
beam span --- 12m
number of equal beam segments --- take 10 parts of concentrated force --- 4
array of force values from left to right --- 82kn, 82kn, 82kn
array of force spacing from left to right --- 3.5m, 1.5m, 3.5m
3 Calculation of internal force and drawing of internal force diagram
the calculation program of bending moment envelope diagram of simply supported beam written by visual basic can be directly run in Windows 98 environment after transforming into exe file. Click this application to pop up a calculation window, as shown in Figure 2. After inputting data, press the calculation button to get the maximum bending moment value of equal section
Fig. 2
according to the calculated results, the envelope diagram of internal force diagram of continuous beam can be drawn
example 2: a highway bridge bears the load of class 15 motorcade in the code for design of highway bridges, as shown in Figure 3. Try to use the source program to calculate and draw its internal force envelope diagram The motorcade can enter the bridge from left or right, and select two ways to enter the bridge for calculation.
8. It's in the user's manual. Read the manual more. I hope it can help you -- ast structure
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