2.0 MODULAR SUPPORT TECHNOLOGY 2.2 EVALUATIONS OF TECHNICAL DATA
Modular Support Systems Technical Guide , Edition 1
All technical data provided in this Technical Guide is based on analytical calculations , finite element analysis , or testing by Hilti or by contracted testing laboratories using testing procedures and construction materials representative of current practice in North America . Published loads are provided for independent loading directions . The design professional shall consider appropriate interaction equations when loading is applied in multiple directions .
Analytical Calculations
Analytical calculations based on the provisions of AISI S100-16 ( for USA ) and CSA S136-16 ( for Canada ) are permitted for determining the load capacities of cold-formed steel members .
Finite Element Analysis
In accordance with AISI S100-16 / CSA S136-16 , rational engineering analysis based on appropriate theory and engineering judgment is permitted as an alternative to testing and analytical methods for obtaining design load data . Accordingly , finite element analyses were performed to derive the technical data for several connector components contained herein .
Testing
In accordance with AISI S100-16 / CSA S136-16 Chapter K , data based solely on tests represents the average results of at least three identical specimens , provided that no individual test result deviates from the average value of all tests by more than 15 percent . Once an average value of all acceptable tests made is determined , a nominal strength , R n
, for the series of tests is obtained . The coefficient of variation , V P
, of the test results is then determined by statistical analysis .
Data based on rational engineering analysis with confirmatory tests is based on a minimum of three tests . A correlation coefficient , C c
, based on the tested strength , R t , is compared to the nominal strength , R n
, predicted from rational engineering analysis models . The correlation between C c and
R t
, must be greater than or equal to 0.80 .
For allowable strength design ( ASD ), the allowable strength value , R a
, is then computed as follows :
The safety factor , Ω , is derived from the following equation :
Where the resistance factor , Φ :
And :
C Φ
= Calibration coefficient
M m
= Mean value of material factor
F m
= Mean value of fabrication factor
P m
= Mean value of professional factor e = Natural logarithmic base
β o
= Target reliability index
V M
= Coefficient of variation of material factor
V F
= Coefficient of variation of fabrication factor
C P
= Correction factor
V P
= Coefficient of variation of test results
V Q
= Coefficient of variation of load effect
The correlation coefficient , C c :
Where :
C c
=
R a
= R n Ω
Ω = 1 . 6 ϕ ϕ = C ϕ ( M m
F m
P m
) e -β V 2 2 2 2 + V o M F
+ C P
V P
+ V Q n Σ R t , i
R n , i
- ( Σ R t , i ) ( Σ R n , i
) n ( Σ R t , i2 ) - ( Σ R t , i
) 2 n ( Σ R n , i2 ) - ( Σ R n , i
) 2 n = Number of tests
R t , i
= Tested strength ( resistance ) of test i
R n , i
= Calculated nominal strength ( resistance ) of test i per rational engineering analysis model
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