# Acceleration for the evaluation of the dynamic comfort

Hello,Previously (in LIRA 9.6) there was description of module 25 in the reference (pulsation in accordance to actualized SP loads and impacts), where:                                                      Quote When calculating accelerations (p. 11.1.8 b and c) for the evaluation of dynamic comfort of people stay in buildings the building, software multiplies...

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Acceleration for the evaluation of the dynamic comfort

Hello,
Previously (in LIRA 9.6) there was description of module 25 in the reference (pulsation in accordance to actualized SP loads and impacts), where:

Quote
When calculating accelerations (p. 11.1.8 b and c) for the evaluation of dynamic comfort of people stay in buildings the building, software multiplies acceleration by a factor equal to 0.7.

There is no such a module in SAPR. The description of module 21 in LIRA 9.6 and SAPR coincides and there is no information about coefficient 0.7.

The question in the following.Was this multiplication before?How this question is now solved in SAPR? Multiplied or not?
 ander Guru Posts: 1506 Points: 2551 Joined: May 31, 2007 #2 People who like this:/ Mar 12, 2015 15:23:11 according to the comparison of calculation results:in the module 25 of LIRA 9.6 the value of the acceleration was multiplied by the coefficient 0.7. in the module 21 of SAPR there is no multiplication.
 Åâãåíèé Ñòðåëåöêèé Regula visitor Posts: 124 Points: 148 Joined: May 14, 2009 #3 People who like this:/ Mar 13, 2015 10:56:27 Hello, 1. There is no module 25 in LIRA-SAPR. The pulsation including actualized is calculated in accordance to module 21. 2. Since in LIRA-FEM we set design loads and masses then there are calculated design pulsation components and design acceleration for pulsation. 3. If you set characteristic value of wind load and characteristic mass weight, then you will get characteristic values of pulsation components and characteristic values of accelerations for pulsation. Sincerely, E. Streletskii.

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Åâãåíèé Ñòðåëåöêèé wrote:
3. If you set characteristic value of wind load and characteristic mass weight, then you will get characteristic values of pulsation components and characteristic values of accelerations for pulsation.

I have to disagree. Yes, what is written is true, but not entirely.
Previously (in LIRA 9.6 and exactly in module 25) there was took into account the coefficient 0.7 (it is not related to the reciprocal of the safety factor for the wind load = 1.4) and here’s why, it is put in the formula 11.14, where it is written, that “characteristic value of pulsation component of wind load” is multiplied by 0.7, which is obtained from the formula 11.5 and this formula is obtained from 11.2 respectively. There is no safety factor in those formulas. The information is given only in p. 11.1.12.
The module 21 does not take into account this coefficient. So, if we calculate according to p.3 as you tell, we won’t get characteristic values of accelerations. Obtained values have to be multiplied by 0.7 manually. Here I am about.
 ðåêñ Expert Posts: 592 Points: 580 Joined: Sep 10, 2007 #5 People who like this:/ Mar 18, 2015 19:33:34 as it seems, if you hold the opinion that the fragility of the construction depends on the stiffness and weight, then the re-introduction of the coefficient of 0.7 for accelerate seems to bertificial.
 ander Guru Posts: 1506 Points: 2551 Joined: May 31, 2007 #6 People who like this:/ Mar 19, 2015 10:51:49 I'm not saying that you need to consider this coefficient when collecting the masses, no, it is necessary to additionally multiply it by obtained acceleration values. It is not clear why it departed from, if before it was implemented in the module 25.
 ðåêñ Expert Posts: 592 Points: 580 Joined: Sep 10, 2007 #7 People who like this:/ Mar 19, 2015 11:12:46 the masses are realistic anyway, stiffness also. The acceleration depends on the magnitude of the applied force, the wind load was set as characteristic value (realistic), the result does not need to be corrected.
 ander Guru Posts: 1506 Points: 2551 Joined: May 31, 2007 #8 People who like this:/ Mar 19, 2015 12:46:45 There is introduced a correction factor in rules - an additional transitional. There are no questions to the rest.
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