scholarly journals Software Module Development for the Parametric Generation of Truss Structure Geometry in a Two-Dimensional Setting

2022 ◽  
Vol 21 (4) ◽  
pp. 376-383
Author(s):  
S. G. Glushko ◽  
A. A. Lyapin ◽  
Yu. Yu. Shatilov ◽  
A. V. Cherpakov ◽  
R. K. Haldkar
Keyword(s):  
Web Application ◽  
Truss Structure ◽  
Truss Structures ◽  
Building Structures ◽  
Two Dimensional ◽  
Software Module ◽  
Parametric Generation ◽  
Design Engineers ◽  
Rod System ◽  
Rod Structures

Introduction. Truss structures are widespread in construction due to a number of advantages, such as economy, versatility, and scalability. Accordingly, their modeling and calculation are urgent tasks in the design of building structures. Automatic solution to these problems causes an increase in design efficiency, calculation accuracy, and lower costs. The objective of the study is to examine the functionality and operation algorithm of the software module developed by the authors that generates the geometry of two-dimensional truss structures for subsequent modeling.Materials and Methods. Following the research of the widespread truss configurations, the classification of chords available in the software under consideration is given. The method of parameterizing a truss structure is provided. This method includes base geometric parameters of the structure such as dimensions, model construction rules, and additional features, as well as a comprehensive algorithm. The software is developed in JavaScript.Results. The software module has been integrated into a web application for calculating two-dimensional rod structures. To illustrate the functionality of the software, the examples of user interface are given as well as an example problem. The example includes configuration and calculation of an inclined truss structure. The results, such as support reactions and internal forces with axial force diagram, are provided.Discussion and Conclusions. Using this software module within the framework of the tool for calculating rod structures allows for the simplified process of modeling and calculating complex truss structures, design time, and resource reduction. The software module provides tools for specifying various types of structures, applying loads and assigning properties of a rod system, which makes it a useful instrument for design engineers.

A Two Step Damage Prognosis Method for Beam-Like Truss Structures

2014 ◽  
Vol 578-579 ◽  
pp. 1092-1095
Author(s):  
Hao Kai Jia ◽  
Ling Yu
Keyword(s):  
Finite Element Method ◽  
Strain Energy ◽  
Truss Structure ◽  
Truss Structures ◽  
Second Step ◽  
The Finite Element Method ◽  
Modal Strain Energy ◽  
Damage Prognosis ◽  
Modal Curvature ◽  
Simulation Results

In this study, a two step damage prognosis method is proposed for beam-like truss structures via combining modal curvature change (MCC) with modal strain energy change ratio (MSECR). Changes in the modal curvature and the elemental strain energy are selected as the indicator of damage prognosis. Different damage elements with different damage degrees are simulated. In the first step, the finite element method is used to model a beam-like truss structure and the displacement modes are got. The damage region is estimated by the MCC of top and bottom chords of a beam-like truss structure. In the second step, the elemental MSECR in the damage region is calculated and the maximum MSECR element is deemed as the damage element. The simulation results show that this method can accurately locate the damage in the beam-like truss structure.

scholarly journals Design of an Interactive Web Application for Teaching Uncertainty Interpretations of Clinical Tests

2021 ◽  
Author(s):  
Sebastian Neher ◽  
Lorenz A. Kapsner ◽  
Hans-Ulrich Prokosch ◽  
Dennis Toddenroth
Keyword(s):  
Medical Students ◽  
Web Application ◽  
Clinical Decision ◽  
Local Learning ◽  
Interactive Software ◽  
Potential Utility ◽  
Software Module ◽  
Future Developments ◽  
Negative Results ◽  
Clinical Investigations

Background: Assessing the uncertainty of diagnostic findings is essential for advising patients. Previous research has demonstrated the difficulty of computing the expected correctness of positive or negative results, although clinical decision support (CDS) tools promise to facilitate adequate interpretations. Objectives: To teach the potential utility of CDS tools to medical students, we designed an interactive software module that computes and visualizes relevant probabilities from typical inputs. Methods: We reviewed the literature on recommended graphical approaches and decided to support contingency tables, plain table formats, tree diagrams, and icon arrays. Results: We implemented these functions in a single-page web application, which was configured to complement our local learning management system where students also access interpretation tasks. Conclusion: Our technical choices promoted a rapid implementation. We intend to explore the utility of the tool during some upcoming courses. Future developments could also model a more complex clinical reality where the likelihood of alternative diagnoses is estimated from sets of clinical investigations.

Hardware Experiments of Autonomous Space Robot – A Demonstration of Truss Structure Assembly –

2000 ◽  
Vol 12 (4) ◽  
pp. 343-350 ◽  
Author(s):  
Kei Senda ◽  
◽  
Yoshisada Murotsu ◽  
Akira Mitsuya ◽  
Hirokazu Adachi ◽  
...  
Keyword(s):  
Experimental System ◽  
Space Robot ◽  
Truss Structure ◽  
Two Dimensional ◽  
Air Bearings ◽  
Vision Sensor ◽  
Space Robots ◽  
Automatic Construction ◽  
System A ◽  
Structure Assembly

This paper addresses an experimental system simulating a free-flying space robot, which has been constructed to study autonomous space robots. The experimental system consists of a space robot model, a frictionless table system, a computer system, and a vision sensor system. The robot model composed of two manipulators and a satellite vehicle can move freely on a two-dimensional planar table without friction by using air-bearings. The robot model has successfully performed the automatic truss structure construction including many jobs, e.g., manipulator berthing, component manipulation, arm trajectory control avoiding collision, assembly considering contact with the environment, etc. The experiment demonstrates the possibility of the automatic construction and the usefulness of space robots.

scholarly journals Semi-Active Friction Damping of Large Space Truss Structures

2004 ◽  
Vol 11 (3-4) ◽  
pp. 173-186 ◽  
Author(s):  
L. Gaul ◽  
H. Albrecht ◽  
J. Wirnitzer
Keyword(s):  
Vibration Suppression ◽  
Flexible Structures ◽  
Truss Structure ◽  
Truss Structures ◽  
Friction Damping ◽  
Large Space ◽  
Normal Forces ◽  
Space Truss ◽  
Active Friction ◽  
Local Feedback

The present approach for vibration suppression of flexible structures is based on friction damping in semi-active joints. At optimal locations conventional rigid connections of a large truss structure are replaced by semi-active friction joints. Two different concepts for the control of the normal forces in the friction interfaces are implemented. In the first approach each semi-active joint has its own local feedback controller, whereas the second concept uses a global, clipped-optimal controller. Simulation results of a 10-bay truss structure show the potential of the proposed semi-active concept.

Truss Structure Health Monitoring Based on Electromechanical Impedance Method

2013 ◽  
Vol 330 ◽  
pp. 357-363
Author(s):  
Cun Fu He ◽  
Xiao Ming Cai ◽  
Shen Yang ◽  
Zeng Hua Liu ◽  
Bin Wu
Keyword(s):  
Neural Network ◽  
Health Monitoring ◽  
Truss Structure ◽  
Truss Structures ◽  
Impedance Method ◽  
Nonparametric Model ◽  
Impedance Spectra ◽  
Frequency Range ◽  
Electromechanical Impedance ◽  
Piezoelectric Elements

Truss structure is widely used in civil engineering applications for its advantages of easy transportation, convenient assembly and uniform loading. However, it is difficult to achieve real-time health monitoring because of connection diversity and complexity of truss structures. As a novel structural health monitoring technique, electro-mechanical impedance method could monitor the health state of one structure by measuring the spectra of impedance or admittance of the piezoelectric elements, which are bonded on the surface of this structure. This approach has the advantages of nonparametric model analysis, easy sensor installation and high local sensitivity, especially in sensitive frequency range. The damage information, which is tested and recorded by using electromechanical impedance method, could convert into intuitive results through neural network because of its good ability for nonlinear mapping. In this paper, a three-layer assembly truss structure was chosen as experimental object, piezoelectric elements were bonded on structure joints to measure structural impedance spectra, the change of these structural impedance spectra was tested and recorded under high frequency excitations when different truss bars were loosed, and then, one back-propagation (BP) neural network was built and trained by this damage information, which were treated as input samples. These results show that the sensitivity of impedance method is not the same to different frequency range and trained neural network could quickly identify loosen truss bars.

Observations by Evaluating the Uncertainty of Stress Distribution in Truss Structures Based on Probabilistic and Possibilistic Methods

2017 ◽  
Vol 2 (3) ◽  
Author(s):  
Sushan Li ◽  
Roland Platz
Keyword(s):  
Monte Carlo ◽  
Stress Distribution ◽  
Normal Stress ◽  
Direct Methods ◽  
Truss Structure ◽  
Truss Structures ◽  
Model Parameters ◽  
Normal Stress Distribution ◽  
Fuzzy Analysis ◽  
Input Parameters

Load-bearing mechanical structures like trusses face uncertainty in loading along with uncertainty in stress and strength, which are due to uncertainty in their development, production, and usage. According to the working hypothesis of the German Collaborative Research Center SFB 805, uncertainty occurs in processes that are not or only partial deterministic and can only be controlled in processes. The authors classify, compare, and evaluate four different direct methods to describe and evaluate the uncertainty of normal stress distribution in simple truss structures with one column, two columns, and three columns. The four methods are the direct Monte Carlo (DMC) simulation, the direct quasi-Monte Carlo (DQMC) simulation, the direct interval, and the direct fuzzy analysis with α-cuts, which are common methods for data uncertainty analysis. The DMC simulation and the DQMC simulation are categorized as probabilistic methods to evaluate the stochastic uncertainty. On the contrary, the direct interval and the direct fuzzy analysis with α-cuts are categorized as possibilistic methods to evaluate the nonstochastic uncertainty. Three different truss structures with increasing model complexity, a single-column, a two-column, and a three-column systems are chosen as reference systems in this study. Each truss structure is excited with a vertical external point load. The input parameters of the truss structures are the internal system properties such as geometry and material parameters, and the external properties such as magnitude and direction of load. The probabilistic and the possibilistic methods are applied to each truss structure to describe and evaluate its uncertainty in the developing phase. The DMC simulation and DQMC simulation are carried out with full or “direct” sample sets of model parameters such as geometry parameters and state parameters such as forces, and a sensitivity analysis is conducted to identify the influence of every model and state input parameter on the normal stress, which is the output variable of the truss structures. In parallel, the direct interval and the direct fuzzy analysis with α-cuts are carried out without altering and, therefore, they are direct approaches as well. The four direct methods are then compared based on the simulation results. The criteria of the comparison are the uncertainty in the deviation of the normal stress in one column of each truss structure due to varied model and state input parameters, the computational costs, as well as the implementation complexity of the applied methods.

scholarly journals Data-Poor Ecological Risk Assessment of Multiple Stressors

2021 ◽  
Author(s):  
Richard E Grewelle ◽  
Elizabeth Mansfield ◽  
Fiorenza Micheli ◽  
Giulio A De Leo
Keyword(s):  
Risk Assessment ◽  
Ecological Risk ◽  
Ecological Risk Assessment ◽  
Web Application ◽  
Multiple Stressors ◽  
Freshwater Ecosystems ◽  
Valuable Insight ◽  
Software Module ◽  
Cumulative Impact ◽  
Comparative Results

Ecological Risk Assessment is a formal process widely applied to terrestrial, marine, and freshwater ecosystems to evaluate the likelihood of adverse ecological effects occurring as a result of exposure to natural or anthropogenic stressors. For many species, data is sparse and semi-quantitative methodologies provide valuable insight for ecosystem management. Recent statistical developments have improved the quality of these analyses yet a rigorous theoretical framework to assess the cumulative impact of multiple stressors is lacking. We present EcoRAMS, a web application and open-source software module that provides easy-to-use, statistically-robust ecological risk assessments of multiple stressors in data-poor contexts. The software receives attribute scores for two variables (e.g. exposure-sensitivity, productivity-susceptibility, severity-likelihood) via CSV templates and outputs results according to a probabilistic metric of risk. We demonstrate comparative results across a range of assumptions, using simulated and empirical datasets including up to five stressors. Accounting for multiple stressors even when data is limited provides a more detailed analysis of risk that may otherwise be understated in single stressor analyses. This application will allow quantification of risk across data-poor contexts for which statistical results have been previously unavailable. The web app format of EcoRAMS.net lowers the barrier of use for practitioners and scientists at any level of statistical training.

scholarly journals USING OPENSTREETMAP DATA TO GENERATE BUILDING MODELS WITH THEIR INNER STRUCTURES FOR 3D MAPS

2017 ◽  
Vol IV-2/W4 ◽  
pp. 411-416 ◽  
Author(s):  
Z. Wang ◽  
A. Zipf
Keyword(s):  
Urban Planning ◽  
Web Application ◽  
Incident Management ◽  
Indoor Environments ◽  
Building Structures ◽  
Building Models ◽  
Wide Range ◽  
Building Information ◽  
Building Components ◽  
Indoor And Outdoor

With the development of Web 2.0, more and more data related to indoor environments has been collected within the volunteered geographic information (VGI) framework, which creates a need for construction of indoor environments from VGI. In this study, we focus on generating 3D building models from OpenStreetMap (OSM) data, and provide an approach to support construction and visualization of indoor environments on 3D maps. In this paper, we present an algorithm which can extract building information from OSM data, and can construct building structures as well as inner building components (e.g., doors, rooms, and windows). A web application is built to support the processing and visualization of the building models on a 3D map. We test our approach with an indoor dataset collected from the field. The results show the feasibility of our approach and its potentials to provide support for a wide range of applications, such as indoor and outdoor navigation, urban planning, and incident management.

scholarly journals Flexural Capacities of Reinforced Concrete Two-Way Bubbledeck Slabs of Plastic Spherical Voids

2013 ◽  
Vol 6 (2) ◽  
pp. 9-20
Author(s):  
Amer M. Ibrahim ◽  
Nazar K. Ali ◽  
Wissam D. Salman
Keyword(s):  
Ultimate Load ◽  
Compressive Strain ◽  
Bubble Diameter ◽  
Crack Pattern ◽  
The Self ◽  
Flexural Behavior ◽  
Slab Thickness ◽  
Building Structures ◽  
Two Dimensional ◽  
Spherical Voids

This paper presents the flexural capacities of R.C two way hollow slabs of plastic spherical voids, also known as BubbleDeck slab system. Recently, various types of slab systems which can reduce the self-weight of slabs have been studied as the height and width of building structures rapidly increase (1). A biaxial hollow slab system is widely known as one of the effective slab systems which can reduce the self-weight of slabs (1). A BubbleDeck slab has a two-dimensional arrangement of voids within the slabs to reduce self-weight (2). The behavior of BubbleDeck slabs is influenced by the ratio of bubble diameter to slab thickness. To verify the flexural behavior of this BubbleDeck slab such as ultimate load, deflection, concrete compressive strain and crack pattern, two-dimensional flexural tests were tested by using special loading frame. Six test of specimens were used. Two were a conventional RC slab and four were BubbleDeck slabs having void diameter to slab thickness ratios of (0.51, 0.64 and 0.80). Results have shown that the crack pattern and flexural behavior depend on the void diameter to slab thickness ratio. The ultimate load capacities for BubbleDeck slabs having bubble diameter to slab thickness of (0.٥1 and 0.64) were the same of solid slabs, while when bubble diameter to slab thickness of (0.80) the ultimate capacities were reduced by about (10%).

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