Envelope example

These document attempts to bring to user, a easy going way of controlling the envelope utility. That is the reason why the examples ahead has been performed. In first, an example with the Totals max/min envelope type will be shaped.

The example consists of a beam 2 meters long made out of steel and a IPE 220 section:

The applied loads will be specified ahead:

The beam is double and simply supported, respectively, in its endings.

Three different load cases are defined, adding the LoadGroup_1 in the first Load Case, the LoadGroup_2 in the second Load case and the LoadGroup_3 in the third one. After solving, we use the Envelope utility:

The three Load Cases are attached and the Envelope type is shaped with the detailed information on the image from above. In this example maximum absolute values in movements, minimum absolute values in stresses and strains and maximum values in bending and moments, will be applied on the envelope.

For this purpose: movements, von misses and bending moments; will be visualized ahead:

Movements:

The envelope has been shaped from the maximum values of the amount of load states, obtaining the results ahead:

Bending moment in Z axis:

The envelope has been shaped from the maximum values of the amount of load states, obtaining the results ahead:

Von mises equivalent stress:

The envelope has been shaped from the maximum values of the amount of load states, obtaining the results ahead:

We are comparing the Von mises equivalent stresses in the first IP, therefore this table with the Von mises values in the first IP, for all the previous cases, will be visualized:

Structural Element	Element	Node	End	At IP 0 Load_1	At IP 0 Load_2	At IP 0 Load_3	At IP 0 MaxMin_Envelope
				MPa	MPa	MPa	MPa
Beam	1	1	0	1479.949	1151.071	822.194	822.194
Beam	1	2	1	5523.244	4295.856	3068.469	3068.469
Beam	2	2	0	8154.264	6597.999	4712.857	4712.857
Beam	2	3	1	11299.049	9742.783	6959.132	6959.132
Beam	3	3	0	13272.314	12044.927	8603.519	8603.519
Beam	3	4	1	15518.589	15189.712	10849.794	10849.794
Beam	4	4	0	16834.099	15847.467	12494.181	12.494.181
Beam	4	5	1	18181.863	14499.702	14740.456	14499.702
Beam	5	5	0	18839.620	13513.070	16384.844	13513.070
Beam	5	6	1	19288.875	12165.304	18631.119	12165.304
Beam	6	6	0	19288.875	11178.671	20275.507	11178.671
Beam	6	7	1	18839.620	9830.907	22521.782	9830.907
Beam	7	7	0	18181.863	8844.274	24166.169	8844.274
Beam	7	8	1	16834.099	7496.509	26412.444	7496.509
Beam	8	8	0	15518.589	6509.876	10849.794	6509.876
Beam	8	9	1	13272.314	5162.111	8603.519	5162.111
Beam	9	9	0	11299.049	4175.479	6959.132	4175.479
Beam	9	10	1	8154.264	2827.714	4712.857	2827.714
Beam	10	10	0	5523.244	1841.081	3068.469	1841.081
Beam	10	11	1	1479.949	493.316	822.194	493.316

As it can be seen, the envelope has been shaped from the minimum values of the amount of load states.

Once the example carrying out the Totals max/min envelope type, we will branch into the example with the Concomitant envelope type. The same structure has been taking, even materials, sections and loads, giving rise to the same load states. However, this load states will deal with the concomitant option. The algorithm of this option will perform the results attending to a criterion for a specific option from the forces and moments drop down.

In relation to this example, we are looking for the maximum values of the Bending moment about the local Z-axis. The envelope for this result type, will be shaped taking the maximum moments from the whole amount of load states, for every element. The concomitant reactions would be those which led to these maximum bending moment. That is the reason why the rest of the forces and moments results will be shaped from these concomitant results.

Bending moment in Z axis:

Maybe plots are a bit difficult to read into. Nevertheless, table results pretend to be more intuitive and easy going as a result of get the concept properly well.

Structural Element	Element	Node	End	Z-BendMoment L1	Z-BendMoment L2	Z-BendMoment L3	Z-BendMoment Envelope
				kN·m	kN·m	kN·m	kN·m
Beam	1	1	0	0.000	0.000	0.000	0.000
Beam	1	2	1	1.800.000	1400.000	1000.000	1800.000
Beam	2	2	0	1800.000	1400.000	1000.000	1800.000
Beam	2	3	1	3200.000	2800.000	2000.000	3200.000
Beam	3	3	0	3200.000	2800.000	2000.000	3200.000
Beam	3	4	1	4200.000	4200.000	3000.000	4200.000
Beam	4	4	0	4200.000	4200.000	3000.000	4200.000
Beam	4	5	1	4800.000	3600.000	4000.000	4800.000
Beam	5	5	0	4800.000	3600.000	4000.000	4800.000
Beam	5	6	1	5000.000	3000.000	5000.000	5000.000
Beam	6	6	0	5000.000	3000.000	5000.000	5000.000
Beam	6	7	1	4800.000	2400.000	6000.000	6000.000
Beam	7	7	0	4800.000	2400.000	6000.000	6000.000
Beam	7	8	1	4200.000	1800.000	7000.000	7000.000
Beam	8	8	0	4200.000	1800.000	-3000.000	4200.000
Beam	8	9	1	3200.000	1200.000	-2000.000	3200.000
Beam	9	9	0	3200.000	1200.000	-2000.000	3200.000
Beam	9	10	1	1800.000	600.000	-1000.000	1800.000
Beam	10	10	0	1800.000	600.000	-1000.000	1800.000
Beam	10	11	1	0.000	0.000	0.000	0.000

As it can be seen, maximum values for every element, in relation to the Bending moment in the local Z axis, have been taken into account when the concomitant envelope has been processed. The rest of the results would be shaped with the concomitant values.