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
2023
18