Idecad Structural Crack
Before diving into the crack culture, let’s understand the software itself.
ideCAD Structural is an integrated Building Information Modeling (BIM) software that allows engineers to:
In the preliminary design phase, ideCAD uses linear elastic analysis to compute maximum tensile stresses in concrete. If the tensile stress exceeds the mean concrete tensile strength ((f_ctm)), cracking is inevitable. The software warns the engineer and suggests increasing member dimensions or adjusting support conditions to reduce tensile stresses before steel is placed. This is crucial for water-retaining structures (pools, tanks), where zero-tension design is often mandated. idecad structural crack
For advanced seismic analysis (Performance-Based Design), ideCAD allows users to "look at" the structural behavior after cracking occurs. Concrete elements crack during an earthquake, reducing their stiffness.
Consider a 200 mm thick RC slab for an underground water tank with a crack width limit of 0.2 mm. A traditional engineer might use minimum reinforcement (Ø12@200 mm). However, ideCAD’s crack analysis for the quasi-permanent load combination (full water pressure + self-weight) calculates a differential strain of 0.0012. Given a 40 mm cover and Ø12 bars, the predicted crack width is 0.28 mm—exceeding the limit. The software instantly suggests two solutions: Before diving into the crack culture, let’s understand
IdeCAD compares the cost and constructability of both options, allowing the engineer to choose. After redesign, the software re-checks and confirms compliance. This iterative process, which might take hours manually, is reduced to seconds.
Before delving into software commands, one must understand the model ideCAD uses. The software does not simulate individual discrete cracks (a computationally prohibitive task for full buildings). Instead, it employs a smeared crack model for global analysis, where the effect of many micro-cracks is averaged over a finite element. For serviceability checks, ideCAD switches to a strain-based, bond-dependent calculation, strictly following the chosen national code (TS500, Eurocode 2, ACI 318, etc.). This allows you to visually see where structural
The fundamental crack width equation, as implemented in ideCAD, derives from the slip theory:
[ w_k = s_r,max \cdot (\varepsilon_sm - \varepsilon_cm) ]
Where:
IdeCAD automates the calculation of (s_r,max) based on concrete cover, bar spacing, and the bond factor of the reinforcement. It then iterates through all serviceability load combinations (rare, quasi-permanent, or frequent) to compute the differential strain. The output is not a single number but a contour plot of predicted crack widths across beams, slabs, and walls.