scholarly journals THE PROPERTIES OF GEOMETRICALLY MODELLING COMPUTATIONAL SCHEMES FOR BUILDING STRUCTURES

2021 ◽  
Vol 12 (1) ◽  
pp. 32-38
Author(s):  
Vladimir Popov ◽  
Eduard Kriksunov ◽  
Tatjana Grigorjeva

For launching a project on a structural object, the calculation of building structures stands as one of the most important stages of project development. In order to correctly analyse structural behaviour, determine the stress-strain state and solve design or inspection problems, the designer is forced to adequately formalize the actual structure turning it into a faultless computational scheme. Virtual testing is one of the main features of the single graphical-information model. Interoperable systems for three-dimensional modelling and analysis, calculation and design ensure smooth data transfer between the physical and computational model. Modern object-modelling techniques and integrated analysis systems allow achieving the defined goal. The article deals with the forms of data exchange, the developmental features of the designed and computational (analysis) BIM model, the integrated design process of CAD/CAE as well as the conversion problems of the physical and computational model.

2013 ◽  
Vol 19 (6) ◽  
pp. 811-822 ◽  
Author(s):  
Mohammed Jameel ◽  
A. B. M. Saiful Islam ◽  
Mohammed Khaleel ◽  
Aslam Amirahmad

A multi-storey building is habitually modelled as a frame structure which neglects the shear wall/slab openings along with the inclusion of staircases. Furthermore, the structural strength provided by shear walls and slabs is not precisely incorporated. With increasing building height, the effect of lateral loads on a high-rise structure increases substantially. Inclusion of shear walls and slabs with the frame leads to improved lateral stiffness. Besides, their openings may play imperative role in the structural behaviour of such buildings. In this study, 61 multi-storey building configurations have been modelled. Corresponding analyses are performed to cope with the influence of shear walls, slabs, wall openings, masonry walls and staircases in addition to frame modelling. The finite element approach is used in modelling and analysis. Structural responses in each elemental combination are evaluated through equivalent static and free vibration analyses. The assessment reveals that inclusion of only slab components with frame modelling contributes trivial improvement on structural performance. Conversely, the presence of shear wall slabs with frame improves the performance noticeably. Increasing wall openings decreases the structural responses. Furthermore, it is not recommended to model staircases in addition to frame–slab–shear wall modelling, unless the effect of wall openings and slab openings is adequately considered.


1999 ◽  
Vol 39 (4) ◽  
pp. 193-201
Author(s):  
P. J. A. Gijsbers

The need for integrated analysis poses a request for integration of computer models, paying extra attention to interfaces, data management and user interaction. Sector wide standardization using data dictionaries and data exchange formats can be a great help in streamlining data exchange. However, this type of standardization can have some drawbacks for a generic framework for model integration. Another concept, called Model Data Dictionary (MDD), has been developed as an alternative for proper data management. The concept is a variant on the federated database concept, a concept where local databases maintain their autonomy, while an interconnection database provides a link for sharing data. The MDD is based on a highly generic data model for geographic referenced objects, which if needed facilitates mapping of the sector wide data dictionary. External interfaces provide, in combination with a data format mapping component, a link to SQL-based data sources and model specific databases. A generic Object Data Editor (ODE), linked to the MDD, has been proposed for provision of a common data editing facility for mathematical models. A test version of the combined MDD/ODE-concept has shown the applicability for integration of all kinds of geographic object oriented mathematical models (both simulation and optimization).


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Doo-Hwan Kim ◽  
Eunseo Gwon ◽  
Junheok Ock ◽  
Jong-Woo Choi ◽  
Jee Ho Lee ◽  
...  

AbstractIn children with mandibular hypoplasia, airway management is challenging. However, detailed cephalometric assessment data for this population are sparse. The aim of this study was to find risk factors for predicting difficult airways in children with mandibular hypoplasia, and compare upper airway anatomical differences using three-dimensional computed tomography (3D CT) between children with mandibular hypoplasia and demographically matched healthy controls. There were significant discrepancies in relative tongue position (P < 0.01) and anterior distance of the hyoid bone (P < 0.01) between patients with mandibular hypoplasia and healthy controls. All mandibular measures were significantly different between the two groups, except for the height of the ramus of the mandible. After adjusting for age and sex, the anterior distance of hyoid bone and inferior pogonial angle were significantly associated with a difficult airway (P = 0.01 and P = 0.02). Quantitative analysis of upper airway structures revealed significant discrepancies, including relative tongue position, hyoid distance, and mandible measures between patients with mandibular hypoplasia and healthy controls. The anterior distance of the hyoid bone and inferior pogonial angle may be risk factors for a difficult airway in patients with mandibular hypoplasia.


2013 ◽  
Vol 40 (7) ◽  
pp. 655-662
Author(s):  
George K. Georgoussis

Building structures of low or medium height are usually designed with a pseudostatic approach using a base shear much lower than that predicted from an elastic spectrum. Given this shear force, the objective of this paper is to evaluate the effect of the element strength assignment (as determined by several building codes) on the torsional response of inelastic single-storey eccentric structures and to provide guidelines for minimizing this structural behaviour. It is demonstrated that the expected torque about the centre of mass (CM) may be, with equal probability, positive (counterclockwise) or negative (clockwise). This result means that the torsional strength should also be provided in equal terms in both rotational directions, and therefore the base shear and torque (BST) surface of a given system must be symmetrical (or approximately symmetrical). In stiffness-eccentric systems, appropriate BST surfaces may be obtained when a structural design is based on a pair of design eccentricities in a symmetrical order about CM, and this is shown in representative single-storey building models under characteristic ground motions.


2013 ◽  
Vol 319 ◽  
pp. 599-604
Author(s):  
Makhsuda Juraeva ◽  
Kyung Jin Ryu ◽  
Sang Hyun Jeong ◽  
Dong Joo Song

A computational model of existing Seoul subway tunnelwas analyzed in this research. The computational model was comprised of one natural ventilationshaft, two mechanical ventilationshafts, one mechanical airsupply, a twin-track tunnel, and a train. Understanding the flow pattern of the train-induced airflow in the tunnel was necessary to improve ventilation performance. The research objective wasto improve the air quality in the tunnel by investigating train-induced airflow in the twin-track subway tunnel numerically. The numerical analysis characterized the aerodynamic behavior and performance of the ventilation system by solving three-dimensional turbulent Reynolds-averaged Navier-Stokes equations. ANSYS CFX software was used for the computations. The ventilation and aerodynamic characteristics in the tunnel were investigated by analyzing the mass flowrateat the exits of the ventilation mechanicalshafts. As the train passed the mechanical ventilation shafts, the amount of discharged-air in the ventilationshafts decreased rapidly. The air at the exits of the ventilation shafts was gradually recovered with time, after the train passed the ventilation shafts. The developed mechanical air-supply for discharging dusty air and supplying clean airwas investigated.The computational results showed that the developed mechanical air-supplycould improve the air quality in the tunnel.


2005 ◽  
Vol 89 (2) ◽  
pp. 1389-1397 ◽  
Author(s):  
Muhammad H. Zaman ◽  
Roger D. Kamm ◽  
Paul Matsudaira ◽  
Douglas A. Lauffenburger

2017 ◽  
Vol 14 (130) ◽  
pp. 20170202 ◽  
Author(s):  
Joseph Libby ◽  
Arsalan Marghoub ◽  
David Johnson ◽  
Roman H. Khonsari ◽  
Michael J. Fagan ◽  
...  

During the first year of life, the brain grows rapidly and the neurocranium increases to about 65% of its adult size. Our understanding of the relationship between the biomechanical forces, especially from the growing brain, the craniofacial soft tissue structures and the individual bone plates of the skull vault is still limited. This basic knowledge could help in the future planning of craniofacial surgical operations. The aim of this study was to develop a validated computational model of skull growth, based on the finite-element (FE) method, to help understand the biomechanics of skull growth. To do this, a two-step validation study was carried out. First, an in vitro physical three-dimensional printed model and an in silico FE model were created from the same micro-CT scan of an infant skull and loaded with forces from the growing brain from zero to two months of age. The results from the in vitro model validated the FE model before it was further developed to expand from 0 to 12 months of age. This second FE model was compared directly with in vivo clinical CT scans of infants without craniofacial conditions ( n = 56). The various models were compared in terms of predicted skull width, length and circumference, while the overall shape was quantified using three-dimensional distance plots. Statistical analysis yielded no significant differences between the male skull models. All size measurements from the FE model versus the in vitro physical model were within 5%, with one exception showing a 7.6% difference. The FE model and in vivo data also correlated well, with the largest percentage difference in size being 8.3%. Overall, the FE model results matched well with both the in vitro and in vivo data. With further development and model refinement, this modelling method could be used to assist in preoperative planning of craniofacial surgery procedures and could help to reduce reoperation rates.


Author(s):  
Srinivasa P. Varanasi ◽  
Athamaram H. Soni

Abstract Data exchange between different CAD systems usually requires conversion between different representations of free-form curves and surfaces. Also, trimmed surfaces give rise to high degree boundary curves. Accurate conversion of these forms becomes necessary for reliable data transfer. Also important is the issue of shape control, specially in the aircraft industry. The objective of this paper is to investigate conversion methods and effect of shape control on the design and choice of such methods.


1993 ◽  
Vol 47 (8) ◽  
pp. 1093-1099 ◽  
Author(s):  
Antony N. Davies ◽  
Peter Lampen

Following the development and publication of the JCAMP-DX protocol 4.24 and its successful implementation in the field of infrared spectroscopy, data exchange without loss of information, between systems of different origin and internal format, has become a reality. The benefits of this system-independent data transfer standard have been recognized by workers in other areas who have expressed a wish for an equivalent, compatible standard in their own fields. This publication details a protocol for the exchange of Nuclear Magnetic Resonance (NMR) spectral data without any loss of information and in a format that is compatible with all storage media and computer systems. The protocol detailed below is designed for spectral data transfer, and its use for NMR imaging data transfer has not as yet been investigated.


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