نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه معماری، دانشکده فنی و مهندسی، دانشگاه قم، قم، ایران
2 گروه معماری، دانشکده امام خمینی،دانشگاه قم، شهر قم
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
1 Aims
The inherent limitations of brick and mortar necessitate the strategic use of geometry to overcome their weaknesses. This paper is specifically centered on discerning the role of geometry in the Panj-O-Haft arch and the Karbandi vault within Persian architectural practices. Notably, the study seeks to explore the intricate correlation between the base arc angle and the structural functionality of the Karbandi, emphasizing the profound influence of varying angles on the dimensions and strength of architectural elements.
2 Methodology
This study utilizes parametric and algorithmic design methods to analyze the Panj-O-Haft arch and its application as ribs for the Karbandi. A structural analysis algorithm is developed to connect with the modeling algorithm, allowing for the examination of various base arc angles and their impact on the structural analysis results. By selecting a base angle range of 20 to 70 degrees, the study generates 50 different Karbandi analysis results, which are then compared based on axial force in Karbandi elements and the thrust vector amount in supports. The research employs linear models and utilizes the Karamba3D plug-in for analysis.
3 Results and Discussion
The Karbandi features interconnected rib geometry, with all ribs dividing into 72 sub-elements. Altering the base arch angle impacts the geometry of these sub-elements and the Shamseh (a type vault) above them, leading to varying ranges of axial force in the sub-elements across different Karbandi models. A smaller range of axial force in the sub-elements indicates a more even force distribution. The study reveals that base arc angles within the 50 to 53 range result in the lowest range of axial force and are the most suitable option for the Panj-O-Haft arch as a rib in the Karbandi. Notably, the traditional base arc degrees for this arch (45 and 54.7) closely align with the optimized range for the base arc.
In every two-leg Karbandi, there are a total of 8 supports, regardless of its division. Due to the symmetrical geometry and topology of the Karbandi, all supports exhibit an equal amount of thrust in different directions within a horizontal plane. A specific support is chosen for comparing thrust amounts in various Karbandi models. The lowest thrust within the 20-to-70-degree angle range is observed at 20 degrees, as this smaller angle tends to straighten the Panj-O-Haft, reducing its curvature and enabling it to withstand higher force. Conversely, within the 42 to 51-degree range, the thrust amount remains relatively consistent and even slightly decreases.
4 Conclusion
This paper presents structural evidence supporting the drawing logic and geometry of the Panj-O-Haft arch. In addition to other factors such as aesthetics, construction technique, material, and dimensions, structural functionality is a crucial aspect linked to the arch's geometry. The selected arch features two base arc angles, namely 45 and 54.7 degrees. The results indicate that these angles are positioned close to the optimal range and exhibit lower thrust amounts at the support location compared to higher angles. While these two arch types may not excel in a single factor, they demonstrate multifaceted functionality and achieve an overall high rating.
کلیدواژهها [English]
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