Group 1 General) is taken for ordinary stress check as well as for stress checks for pre-stressing tendons (action FIBCHK and
3.6.2 Intrinsic Variables and Functions
3.6.2.1 Intrinsic Variables
Intrinsic Variables are variables used in RM2000, which may be referenced by the user as independent (abscissa) values or function arguments for computing other (user de- fined) variables. Some of these variables are variables setup and used in the calculation process (such as the natural frequency OMEGA used in earthquake analyses for evaluat- ing a response spectrum), others are simply input in the RM2000 GUI and stored in the database to be passed to the variable evaluation process when needed.
Attention: The values of intrinsic Variables are not transformed to the user defined unit system, when they are passed from the calcu- lation unit of RM2000 to the variable evaluation process. I.e.
they are always defined in the default units (kN, m, sec, days), as specified below in detail.
Table of intrinsic Variables:
t Age of the material (concrete) of the considered element at the actual time. Used for creep analysis. [days]
t0 Age of the material (concrete) of the considered element at the application time of the actual Load Case. Used for creep analy- sis. [days]
ts Age of the material (concrete) of the considered element when shrinkage theoretically starts (this is not the start of the consid- eration of shrinkage!). Used for creep analysis. [days]
tstart Absolute time (on the global time axis, i.e. relative to day ‘0’ of the construction schedule) when a certain action takes place. Ac- tually not used. [days]
E28 Basic value of the Young’s Modulus used in the calculation.
(Usually for concrete the value at an age of 28 days). [kN/m2] Ax (Average) cross-section area of the considered element [m2] Fc28 Design value of compressive strength of the material of the con-
sidered element. (Usually for concrete at an age of 28 days).
[kN/m2]
CF Consistency coefficient of the fresh concrete for the considered element. Used for creep analysis. [-]
U The perimeter of the cross section exposed to drying (for the element being considered). Used for creep analysis. [m]
UIN Summation of the internal (hollow box cross section) perime- ter(s) of the cross section for the element being considered. Used for creep analysis. [m]
RH Average relative humidity (in %) at the construction site for the considered element. Used for creep analysis.
ZF Cement hardening parameter of the material of the considered element. Used for creep analysis. [-]
TMP Average temperature of the environment of the considered ele- ment. Used for creep analysis. [°C]
omega Natural (or angular) frequency for dynamic calculations [omega = (2*PI)/Period].
GAMMA Specific weight of the material of the considered element [kN/m3].
WCR Water cement ratio [-]
CECO Cement content in concrete [Cement weight per concrete vol- ume]
qlen Effective length of UDL traffic loading for the considered result point (used in the evaluation of influence lines for defining the line load of load trains as a function of the loaded length [m]
RPR Product of the reinforcement content (As/Ac) and the ratio of the moduli of elasticity (Es/Ec) – equivalent to the ratio of the nor- mal force stiffness of steel and concrete (As*Es/Ac*Ec). Used for creep analysis (Hongkong Standard and British Standard) [-]
RelSig Pre-stressing force utilization level (actual PS-force as a per- centage of allowable force (ratio SIG-pr / SIG-allow-pr * 100)).
Used for steel relaxation analysis. [Consideration actually not implemented!]
All available intrinsic variables can be listed clicking the button at the right top of the lower table. The listing shows the
• Variable name
• the current value (‘0’ if it is unset, any other value if it is set)
• the unit
• and a brief description
This view can be used for checking the actual value of intrinsic variables throughout the analysis progress. Some values may also be modified to check the influence of the modification on other variables or parameters (e.g. the influence of modified material parameters on the creep and shrinkage coefficients). Attention must be paid to the fact, that such modifications are performed only locally, i.e. the changes are not passed to the database. Values from parameter tables of the database (e.g. material parameters like
recalculation process again get the original values, unless the parameters have been changed directly in the parameter table.
3.6.2.2 Intrinsic Functions:
• Basic trigonometric functions “cos()”, “sin()”, “tan()”, “acos()”, “asin()”, “atan()”.
Please note that all angles used as arguments of intrinsic functions must be given in radians! (not in the active I/O angle unit!)
• Basic exponential and logarithmic functions “sqr()”, “ln()”, “log()”, “exp()” with (exp(2.5) = e2.5).
• Logic functions “abs()”, “min()”, “max”, “hright()”, “hleft()”, “dirac()”, “diract()”.
abs(a) gives the absolute value of the argument.
min(a,b) gives the smaller value of the two arguments.
max(a,b) gives the greater value of the two arguments.
hright(a,b) = 1 if a>b, else = 0 hleft(a,b) = 1 if a<b, else = 0
dirac(a,b,eps) =1 if b-eps<a<b+eps, else =0 (Figure 1a).
diract(a,b,eps1, eps2) = triangular interpolation (Figure 1b).
(a) 1
0
dirac() eps
a b
(b) 1
0
diract() eps1
a b
eps2
Figure 1. Logical functions dirac() and diract().