Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NJIT professor says certain home shapes and roofs hold up best in hurricane

20.06.2007
Certain home shapes and roof types can better resist high winds and hurricanes, according to a researcher at New Jersey Institute of Technology (NJIT).

Civil engineer Rima Taher, PhD, special lecturer in the New Jersey School of Architecture at NJIT, spent two years examining the findings of research centers that have studied the best designs and construction materials and methods needed to withstand extreme wind events and hurricanes.

“Although I’d like to say that there is a simple and economical solution for housing that won’t fail or collapse in the perfect storm, such information does not yet exist,” said Taher. “However, it is obvious that thanks to the work of wind engineers and researchers that changes to home design and construction can make buildings safer for people, while saving government and industry billions of dollars annually.”

“Design of Low-Rise Buildings for Extreme Wind Events” (Journal of Architectural Engineering, March, 2007) by Taher highlighted such research findings. Wind researchers at the Center for Building Science and Technology (CSTB) in France, researched and tested reduced-scale home models at its wind tunnel facilities, and developed a prototype of a “cyclonic” or hurricane-resistant dwelling. Taher cooperated with the CSTB wind researchers, working on the structural aspect of the home’s design.

That design eventually became an elevated structure of a square plan form on an open foundation. The home had a hip roof and was equipped with a central shaft with aerodynamic features designed to reduce wind forces during an extreme wind event. Wind tunnel tests at CSTB showed that such a home would be far more efficient under high winds and hurricane conditions than a typical structure. CSTB is working with a builder to construct a prototype of such a home on Réunion in the West Indian Ocean.

From this work and other studies Taher recommends the following construction considerations for homeowners in hurricane-prone regions.

A home with a square floor plan (or better a hexagonal or octagonal plan) with a multiple-panel roof (4 or more panels) was found to have reduced wind loads.

Roofs with multiple slopes such as a hip roof (4 slopes) perform better under wind forces than gable roofs (2 slopes). Gable roofs are generally more common because they are cheaper to build. A 30-degree roof slope has the best results.

Wind forces on a roof tend to be uplift forces. This explains why roofs are often blown off during an extreme wind event. Connecting roofs to walls matters. Stapled roofs were banned following Hurricane Andrew in Florida in 1993.

Strong connections between the structure and its foundation and connections between walls are good. Structural failure is often progressive where the failure of one structural element triggers the failure of another, leading to a total collapse. Connections are generally vulnerable but can be inexpensively strengthened.

Certain areas of a building such as the ridge of a roof, corners and eaves are normally subject to higher wind pressures. In the cyclonic home design, CSTB researchers proposed some aerodynamic features to alleviate these local pressures such as introducing a central shaft which would function by creating a connection between the internal space and the roof ridge considered to be the location of the largest depression. This connection helps balance pressures leading to a significant reduction in the roof’s wind loads.

Roof overhangs are subject to wind uplift forces which could trigger a roof failure. In the design of the hurricane-resistant home, the length of these overhangs should be limited to 20 inches.

The design of the cyclonic home includes simple systems to reduce the local wind stresses at the roof’s lower edges such as a notched frieze or a horizontal grid to be installed at the level of the gutters along the perimeter of the home.

An elevated structure on an open foundation reduces the risk of damage from flooding and storm-driven water.

Sheryl Weinstein | EurekAlert!
Further information:
http://www.njit.edu

More articles from Architecture and Construction:

nachricht Modular storage tank for tight spaces
16.03.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

nachricht Smart homes will “LISTEN” to your voice
17.01.2017 | EML European Media Laboratory GmbH

All articles from Architecture and Construction >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Touch Displays WAY-AX and WAY-DX by WayCon

27.06.2017 | Power and Electrical Engineering

Drones that drive

27.06.2017 | Information Technology

Ultra-compact phase modulators based on graphene plasmons

27.06.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>