Analysis of Sandwich Panels for an Energy Efficient and Self-Supporting Residential Roof

Author(s):  
Daniel Thomas ◽  
Susan C. Mantell ◽  
Jane H. Davidson ◽  
Louise F. Goldberg ◽  
John Carmody

The structural and thermal feasibility of a self-supporting sandwich panel for energy efficient residential roof applications is assessed. The assessment is limited to symmetric sandwich panels comprising two face sheets and an insulating core. Feasible panel designs are presented for loading conditions, corresponding to southern and northern climates in the United States. The base case panel is 5.5 m long for a nominal 4.6 m horizontal span and an 8/12 roof pitch. Face sheet materials considered are oriented strand board, steel, and fiber reinforced plastic. Core materials considered are expanded polystyrene, extruded polystyrene, polyurethane and poly(vinyl-chloride) foams. A wide range of material options meet building code limits on deflection and weight and prevent face sheet fracture and buckling, and core shear failure. Panels are identified that have structural depths similar to conventional wood rafter construction. Shortening the overall panel length provides greater choice in the use of materials and decreases the required panel thickness. Suggestions for improved panel designs address uncertainty in the ability of the plastic core to withstand long term loading over the expected life of residential buildings.

2005 ◽  
Vol 128 (3) ◽  
pp. 338-348 ◽  
Author(s):  
Daniel Thomas ◽  
Susan C. Mantell ◽  
Jane H. Davidson ◽  
Louise F. Goldberg ◽  
John Carmody

The structural and thermal feasibility of a self-supporting sandwich panel for energy efficient residential roof applications is assessed. The assessment is limited to symmetric sandwich panels comprising two face sheets and an insulating core. Feasible panel designs are presented for loading conditions, corresponding to southern and northern climates in the United States. The base case panel is 5.5m long for a nominal 4.6m horizontal span and an 8∕12 roof pitch. Face sheet materials considered are oriented strand board, steel, and fiber reinforced plastic. Core materials considered are expanded polystyrene, extruded polystyrene, polyurethane, and poly(vinyl-chloride) foams. A wide range of material options meet building code limits on deflection and weight and prevent face sheet fracture and buckling, and core shear failure. Panels are identified that have structural depths similar to conventional wood rafter construction. Shortening the overall panel length provides greater choice in the use of materials and decreases the required panel thickness. Suggestions for improved panel designs address uncertainty in the ability of the plastic core to withstand long term loading over the expected life of residential buildings.


Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 70 ◽  
Author(s):  
Robert Studziński ◽  
Tomasz Gajewski ◽  
Michał Malendowski ◽  
Wojciech Sumelka ◽  
Hasan Al-Rifaie ◽  
...  

In this paper, an experimental investigation is presented for sandwich panels with various core layer materials (polyisocyanurate foam, mineral wool, and expanded polystyrene) when subjected to a justified blast load. The field tests simulated the case for when 5 kg of trinitrotoluene (TNT) is localized outside a building’s facade with a 5150 mm stand-off distance. The size and distance of the blast load from the obstacle can be understood as the case of both accidental action and a real terroristic threat. The sandwich panels have a nominal thickness, with the core layer equal 100 mm and total exterior dimensions of 1180 mm × 3430 mm. Each sandwich panel was connected with two steel columns made of I140 PE section using three self-drilling fasteners per panel width, which is a standard number of fasteners suggested by the producers. The steel columns were attached to massive reinforced concrete blocks via wedge anchors. The conducted tests revealed that the weakest links of a single sandwich panel, subjected to a blast load, were both the fasteners and the strength of the core. Due to the shear failure of the fasteners, the integrity between the sandwich panel and the main structure is not provided. A comparison between the failure mechanisms for continuous (polyisocyanurate foam and expanded polystyrene) and non-continuous (mineral wool) core layer materials were conducted.


2019 ◽  
Vol 111 ◽  
pp. 03025
Author(s):  
Annamaria Belleri ◽  
Chiara Dipasquale ◽  
Jennifer Adami

Despite a wide range of energy-efficient technologies, financial products and public incentives are already available, the private as well as the public sector are struggling to invest in energy efficient solutions for buildings. The primary barriers are the high initial cost and the uncertain payback period of the energy refurbishment. Allowing for different scenario testing and considering interactions among different building energy systems, building energy simulation tools can help investors overcoming such barriers by offering support to the technical planning of energy refurbishment kits through quantitative information rather than qualitative. The energy performance and comfort of three reference multifamily residential buildings typologies were evaluated considering three envelope retrofitting performance levels (high-medium-low insulated and airtight) and different heating and domestic hot water systems (heat pump, boiler, district heating). The tested envelope retrofitting performance levels allow for heating need reduction between 50% and 90% compared to the reference case. The active cooling system is not accounted for and building energy simulations outputs include thermal comfort evaluation and overheating risk assessment during the summer season. The potential of photovoltaic system combined with heat pump is evaluated in the three reference cases leading to up to 30% of load coverage.


Author(s):  
Tim Rutherford-Johnson

By the start of the 21st century many of the foundations of postwar culture had disappeared: Europe had been rebuilt and, as the EU, had become one of the world’s largest economies; the United States’ claim to global dominance was threatened; and the postwar social democratic consensus was being replaced by market-led neoliberalism. Most importantly of all, the Cold War was over, and the World Wide Web had been born. Music After The Fall considers contemporary musical composition against this changed backdrop, placing it in the context of globalization, digitization, and new media. Drawing on theories from the other arts, in particular art and architecture, it expands the definition of Western art music to include forms of composition, experimental music, sound art, and crossover work from across the spectrum, inside and beyond the concert hall. Each chapter considers a wide range of composers, performers, works, and institutions are considered critically to build up a broad and rich picture of the new music ecosystem, from North American string quartets to Lebanese improvisers, from South American electroacoustic studios to pianos in the Australian outback. A new approach to the study of contemporary music is developed that relies less on taxonomies of style and technique, and more on the comparison of different responses to common themes, among them permission, fluidity, excess, and loss.


Author(s):  
Kathryn A. Sloan

Popular culture has long conflated Mexico with the macabre. Some persuasive intellectuals argue that Mexicans have a special relationship with death, formed in the crucible of their hybrid Aztec-European heritage. Death is their intimate friend; death is mocked and accepted with irony and fatalistic abandon. The commonplace nature of death desensitizes Mexicans to suffering. Death, simply put, defines Mexico. There must have been historical actors who looked away from human misery, but to essentialize a diverse group of people as possessing a unique death cult delights those who want to see the exotic in Mexico or distinguish that society from its peers. Examining tragic and untimely death—namely self-annihilation—reveals a counter narrative. What could be more chilling than suicide, especially the violent death of the young? What desperation or madness pushed the victim to raise the gun to the temple or slip the noose around the neck? A close examination of a wide range of twentieth-century historical documents proves that Mexicans did not accept death with a cavalier chuckle nor develop a unique death cult, for that matter. Quite the reverse, Mexicans behaved just as their contemporaries did in Austria, France, England, and the United States. They devoted scientific inquiry to the malady and mourned the loss of each life to suicide.


Author(s):  
David Vogel

This book examines the politics of consumer and environmental risk regulation in the United States and Europe over the last five decades, explaining why America and Europe have often regulated a wide range of similar risks differently. It finds that between 1960 and 1990, American health, safety, and environmental regulations were more stringent, risk averse, comprehensive, and innovative than those adopted in Europe. But since around 1990 global regulatory leadership has shifted to Europe. What explains this striking reversal? This book takes an in-depth, comparative look at European and American policies toward a range of consumer and environmental risks, including vehicle air pollution, ozone depletion, climate change, beef and milk hormones, genetically modified agriculture, antibiotics in animal feed, pesticides, cosmetic safety, and hazardous substances in electronic products. The book traces how concerns over such risks—and pressure on political leaders to do something about them—have risen among the European public but declined among Americans. The book explores how policymakers in Europe have grown supportive of more stringent regulations while those in the United States have become sharply polarized along partisan lines. And as European policymakers have grown more willing to regulate risks on precautionary grounds, increasingly skeptical American policymakers have called for higher levels of scientific certainty before imposing additional regulatory controls on business.


Author(s):  
Alison Brysk

In Chapter 7, we profile the global pattern of sexual violence. We will consider conflict rape and transitional justice response in Peru and Colombia, along with the plight of women displaced by conflict from Syria and Central America, and limited international policy response. State-sponsored sexual violence and popular resistance to reclaim public space will be chronicled in Egypt as well as Mexico. We will track intensifying public sexual assault amid social crisis in Turkey, South Africa, and India, which has been met by a wide range of public protest, legal reform, and policy change. For a contrasting experience of the privatization of sexual assault in developed democracies, we will trace campus, workplace, and military rape in the United States.


Author(s):  
Mark Blaxill ◽  
Toby Rogers ◽  
Cynthia Nevison

AbstractThe cost of ASD in the U.S. is estimated using a forecast model that for the first time accounts for the true historical increase in ASD. Model inputs include ASD prevalence, census population projections, six cost categories, ten age brackets, inflation projections, and three future prevalence scenarios. Future ASD costs increase dramatically: total base-case costs of $223 (175–271) billion/year are estimated in 2020; $589 billion/year in 2030, $1.36 trillion/year in 2040, and $5.54 (4.29–6.78) trillion/year by 2060, with substantial potential savings through ASD prevention. Rising prevalence, the shift from child to adult-dominated costs, the transfer of costs from parents onto government, and the soaring total costs raise pressing policy questions and demand an urgent focus on prevention strategies.


2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 313-314
Author(s):  
Darlingtina Esiaka ◽  
Alice Cheng ◽  
Candidus Nwakasi

Abstract Self-acknowledgement and integration of racial and sexual identities are significant to one’s overall sense of identity because of their implications for mental health and wellbeing. These issues are important as one ages because older people experience a wide range of factors that add layers to their ability to (re)integrate subsets of their identity into their overall self-identity such as age and age-related disabilities. This study examined the intersection of race and sexual identities on overall health status in older Black gay men, a demographic group that has historically received less attention. Data from the Social Justice Sexuality (SJS) survey of LGBTQ+ people of color which occurred over a 12-month period in the United States were analyzed. Participants (N=160), 50 years and over, responded to questions about their sexuality, social identity, family dynamics, community connection and engagement, and mental and physical health. Results show an association of mental wellbeing with racial and sexual identities. Further, results show that a strong sense of connection to other sexual minorities is positively associated with mental health in older Black gay men. We discuss the implication of findings for mental health interventions targeting this gendered population.


Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4180
Author(s):  
Joowook Kim ◽  
Michael Brandemuehl

Several building energy simulation programs have been developed to evaluate the indoor conditions and energy performance of buildings. As a fundamental component of heating, ventilating, and air conditioning loads, each building energy modeling tool calculates the heat and moisture exchange among the outdoor environment, building envelope, and indoor environments. This paper presents a simplified heat and moisture transfer model of the building envelope, and case studies for building performance obtained by different heat and moisture transfer models are conducted to investigate the contribution of the proposed steady-state moisture flux (SSMF) method. For the analysis, three representative humid locations in the United States are considered: Miami, Atlanta, and Chicago. The results show that the SSMF model effectively complements the latent heat transfer calculation in conduction transfer function (CTF) and effective moisture penetration depth (EMPD) models during the cooling season. In addition, it is found that the ceiling part of a building largely constitutes the latent heat generated by the SSMF model.


Sign in / Sign up

Export Citation Format

Share Document