Strength analysis of a cylindrical vessel

Calculation of the thickness of the cylindrical wall of a metal vessel (cylinder, tank) from the condition of ensuring its strength

An applet to construct a system of nomograms for calculating the cylindrical wall thickness [mm] - substitution efforts MPa

Formula for calculating the minimum thickness of the cylindrical shell (welded cylindrical wall of the internal pressure vessel)

h_min = P · f · R / (c · s_t), [1]

where

P – the maximum working pressure, kgs/mm² [MPas];

f – assurance coefficient;

R – interior radius of a shell, mm;

c – weld seam strength factor (usually c=0,85);

s_t – yield strength of a material of a shell, kgs/mm² [MPas].

The safety factor f must take into account all possible errors in the calculation of strength and inaccuracies in determining the loading conditions to ensure the integrity of the vessel (no destruction) with a minimum margin of safety.

The yield strength s_t is the stress at which the deformation of the vessel occurs without increasing the load (internal pressure of the vessel in our case).

s_0,2 - this is the stress taken as the conditional yield strength (for materials that do not have a pronounced yield area on the tensile diagram). This is such a stress, after the removal of which the value of the residual deformation of the object is 0.2%. For example, for aluminum alloy AMg6 - s_0.2 = (150...160) MPa.

After starting the applet auxiliary window ( "entry window") will be as follows (Figure 1).

Figure 1. Additional applet window to build a system of nomograms for calculating the minimum wall thickness of a pressure vessel

In the input box already shows the layout of nomograms, but it requires re-entry, so each small square denoting nomogram "clicks" on the right mouse button and the left button "click" on the spot where you want the color box (the location of the value of the parameter Z nomogram). You can choose any other place of the variable parameter Z. location After reappointment scheme nomograms "click" with the left mouse button on the icon "[-]", located in the upper left corner of the nomograms scheme. It will change your view of the "[+]". This means that the circuit is secured nomograms.

Figure 2. Additional applet window on the construction of nomograms system to calculate the minimum thickness of the shell under internal pressure

After fixing the nomograms scheme, consistently "click" on each icon indicating the nomogram, and press the three buttons "in memory", "Substitution of ID", "Total formula" to make all the nomogram parameters in memory and forming calculation formula.

Go to the main window and enter the values of the steps along the axes "X" and "Y". Click on the "Build for ID".

Figure 3. Main applet window for constructing nomograms system for calculating the minimum wall thickness of a pressure vessel.

More detailed instructions for the applet.

An applet to construct a system of nomograms for calculating the cylindrical wall thickness [mm] - substitution efforts MPa

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