RCF HDL 12-AS Owner's Manual page 7

"RCF SHAPE DESIGNER" SOFTWARE AND SAFETY FACTOR
The suspension system is designed to have a proper safety factor (configuration dependent). Using the "HDL50
Shape Designer" software it is very easy to understand safety factors and limits for each specific configuration. To
better comprehend in which safety range the mechanics are working a simple introduction is needed: HDL 6-A arrays'
mechanics are built with certified UNI EN 10025 Steel. RCF prediction software calculates forces on every single
stressed part of the assembly and shows the minimum safety factor for every link. Structural steel has a stress-strain (or
equivalent Force-Deformation) curve as in the following:
In our prediction software the Safety Factors are calculated considering the Maximum Stress Limit equal to the
Yield Strength, according with many international standards and rules.
The resulting Safety Factor is the minimum of all the calculated safety factors, for each link or pin.
This is where you are working with a SF=7
The curve is characterized by two critical points: the Break Point and
the Yield Point. The tensile ultimate stress is simply the maximum stress
attained. Ultimate tensile stress is commonly used as a criterion of the
strength of the material for structural design, but it should be recognized
that other strength properties may often be more important. One of
these is certainly the Yield Strength. Stress-strain diagram of structural
steel exhibit a sharp break at a stress below the ultimate strength. At
this critical stress, the material elongates considerably with no apparent
change in stress. The stress at which this occurs is referred to as the Yield
Point. Permanent deformation may be detrimental, and the industry
adopted 0.2% plastic strain as an arbitrary limit that is considered
acceptable by all regulatory agencies. For tension and compression, the
corresponding stress at this offset strain is defined as the yield.
Depending on local safety regulations and on the situation, the
required safety factor can vary. It is responsibility of the owner or
rigger to make sure that the system is properly rigged in accordance
with Country and local laws and regulations.
The "RCF Shape Designer" software gives detailed information of the
safety factor for each specific configuration.
The results are classified in four classes:
-GREEN: SAFETY FACTOR > 7
-YELLOW 4 > SAFETY FACTOR > 7
-ORANGE 1.5 > SAFETY FACTOR > 4
-RED SAFETY FACTOR < 1.5 NEVER ADMITTED
SUGGESTED