Thesis (M.S.)--Michigan State University. Dept. of Mechanical Engineering, 2007. / Title from PDF t.p. (viewed on Aug. 11, 2009) Includes bibliographical references (p. 85). Also issued in print.

Standard methods for fire resistance testing require large-scale assemblies and are typically conducted on specialized furnaces at considerable cost. This research focused on developing a scaling methodology for a reduced-scale fire resistance test that reduces the size of the test article while maintaining the same thermal and structural response exhibited in the large-scale test. The developed scaling methodology incorporates uniform geometric scaling, Fourier number time scaling, and furnace boundary condition matching. The scaling laws were experimentally validated with fire exposure tests on gypsum wallboard samples at three scales (full-scale, 1/2-scale, and 1/6-scale). Next, these scaling laws were demonstrated for wood with combined thermo-structural loading. Dimensional lumber boards at ½-scale and ¼-scale were subjected to combined bending and thermal loading. Samples were placed in static three-point bending with the loading scaled to have structural similitude, while simultaneously, the bottom surface was exposed to a scaled fire exposure. Analytical modeling of wood pyrolysis demonstrated that, due to char kinetics as the heating rate is increased in the tests, equivalently less char is formed in the reduced-scale tests. Therefore, we developed a char timescale correction factor, calculated from both model predictions and measured charring rates, which modified the previous Fourier number time scaling laws. Finally, we investigated the effect of multi-orientation materials with a similar set of combined thermo-structural three-point bending tests on plywood samples. The stacking sequence of laminated wood significantly impacts the composite mechanical behavior of the material, especially when scaling down thermo-mechanical tests on plywood. A consequence of the different stacking sequences is that the data from the reduced-scale test cannot be directly scaled to predict the behavior of the larger-scale tests. Thus, modeling becomes essential to extrapolating the data from the reduced-scale test to predict the behavior of the larger-scale test. Reduced cross-sectional area models incorporating classical lamination theory were used to predict the mechanical response of the composite samples as the char front increased. / Doctor of Philosophy / How do we know that a structure will be safe during a fire? The response of structures to fire is typically evaluated using large-scale tests with combined thermo-structural loading: one side of the test sample is exposed to a furnace at standard gas temperatures, while at the same time the sample is loaded with a structural load. Fire resistance testing is essential to evaluating if building components can maintain structural integrity and allow people to egress a building safely during a fire. Standard methods for fire resistance testing require large-scale test samples and are typically conducted on specialized furnaces at national testing facilities at considerable cost. In order to support research and development efforts to design new fire-resistant structures, reduced-scale tests are more desirable because they are cost-effective. However, no reduced-scale test exists to evaluate fire resistance. This research focused on developing a methodology for reducing the size of a test with combined thermo-structural loading. The goal is to have a reduced-scale test that provides insight into the thermal and structural behavior of a similar sample in the large-scale test. The test scaling laws were demonstrated with both experiments and modeling. We developed a small-scale furnace setup to conduct combined thermo-structural tests on samples of different scales. To investigate material type, we tested samples made from gypsum wallboard, dimensional lumber, and plywood. This work will ultimately allow manufacturers to replace costly standard fire resistance tests with reduced-scale versions of these tests during the material screening phase.

The role of the interior designer in providing for fire safe interiors is an important one. The textile end-products they specify play an important part in the start and/or spread of interior fires. Furthermore, the rate of developments in textile testing and products makes it difficult for designers to keep abreast of the latest information. This thesis provides a program for updating interior designers on fire safe interior textiles. A one hour update program was developed as part of the thesis and delivered to members of the Southwest Regional Chapter of ASID in Roanoke, Virginia. An analysis of data from a survey showed that participants believe there is a need for an educational program such as this course and that they would attend a five hour CEU course developed on this subject. Responses to questions on textile fibers, standard tests, and new products on the market supported the perceived need for continuing education on the subject of fire safe textiles. The course evaluation in turn, determined that some areas of the program needed to be revised. This thesis provides a packaged program which can be easily updated. Furthermore, anyone with a textile background can use this program in preparing and delivering a CEU course on fire safety and interior textiles. / Master of Science

Compartment fire scenarios are of great interest due to the large loss of life and property that occurs annually in such fires. Due to the current move towards performance-based building code standards and the increasing acceptance by the regulatory system of model results, there is a growing need for detailed compartment fire data to demonstrate the accuracy of such engineering tools as they are used to ascertain performance. A series of carefully designed full-scale room/corner tests on two vinyl ester resin composite systems have been conducted in a heavily instrumented compartment to provide compartment fire data for the calibration of engineering tools. The two composite systems were chosen based on their thermal behavior. A nominally thermally-thick glass-reinforced plastic (GRP) skin was desirable, as many analytical formulations have been developed using semi-infinite assumptions. A "thermally-thin" skin panel typical of that used in fast ferry construction, consisting of a GRP skin over a balsa core, was also tested. The test protocol used throughout the room/corner experiments was a modification of the ISO 9705 standard where the HRR of the ignition fire was varied according to the Critical Ignition Source Strength concept. To date, there has been little work done where heat fluxes from compartment fires have been measured. Therefore, one of the key data components developed in this series of tests are heat flux measurements from thin skin calorimeters. A total of twenty-five thin skin calorimeters, constructed of Inconel plates, were located throughout the room: the spatial distribution of net and incident heat fluxes within compartment for both pre- and post-flashover conditions have been determined. Additionally, rakes of bare-bead thermocouples were placed in the vent and the corner of the room coincident with the thin skin calorimeter arrays. A third rake was placed in the center of the room. The thermocouple arrays provide data regarding layer temperatures and interface heights as well as a limited determination of temperature spatial distribution within the compartment. The thermocouple rakes also permit calculation of pressure gradients across and mass flows through the vent, thus providing information regarding wall lining fire entrainment rates, of use in corner fire algorithm validations and for globally evaluating the accuracy of CFD codes. Bench-scale cone calorimeter (ASTM E1354, ISO 5660) tests have been carried out on the two composite systems to gather material fire properties necessary as model inputs for fire spread algorithms. The present study developed material properties including heat release rate, species production, and ignition data for the two composite systems. Included are uncertainty bands that account for calculation and instrument uncertainty.

How well do calculations methods prescribed in today's design codes and standards represent conditions in natural fires? Can the temperature and behavior of a steel member in fire be predicted from these calculations? A literature review of structural fire codes, full scale fire tests, published fire test data, the function and selection of design fires, mechanical and thermal behaviors of structural steel, and numerical calculation methods for the temperature of steel members was conducted as a foundation to analyze whether a not a structural fire engineer can answer these questions. Through comparisons of published data from four natural fires tests performed at the Cardington test facility in the United Kingdom to numerical calculations based upon prescribed methods from Eurocode 3 and the Swedish Design Manual, time-temperature curves were developed to demonstrate the variation in temperature of the recorded data in the natural fire tests at Cardington to the equivalent members being analyzed with numerical calculation methods. When available, fire compartment characteristics were replicated during numerical calculations to ensure the highest correlation between the recorded and calculated results. An Excel tool was created to rapidly calculate and produce the resulting time-temperature curves as well as yield strength, modulus of elasticity, and load carrying capacity using a variety of input parameters including design fire data and steel member selection. The goal of the Cardington fires study was to provide comparisons of published natural fire data to results of numerical calculation methods from the codes. Additional comparisons were developed using a US Office design to show the effects of changing compartment and design parameters on the steel temperature, yield strength, elastic modulus and load carrying capacity. Differences found in temperature of steel members between the published Cardington data and numerical calculations proved the difficulty of predicting the behavior of a structural steel beam throughout an entire length of a fire or even until failure. Discussion of results addressed the selection of design fires, input parameters, structural layouts of office buildings, heating and cooling phases of steel members, and failure criteria.

In recent decades, many manufacturing industries have globalized their operations and the Canadian manufacturing sector has experienced dramatic downsizing. For a manufacturing company to succeed therefore, it is necessary for them to operate with a global perspective. In the area of fire safety, this requires understanding of, and compliance with, global regulatory requirements. This research develops a systematic approach that can be utilized to analyze and compare the complex fire safety regulatory requirements that are stipulated for a selected topic in various countries. The approach developed is sufficiently general that it can be leveraged to compare and contrast global standards in any field or discipline. The methodology outlines six aspects of the regulatory environment that must be considered in sorting standards and then uses spreadsheets and a mind mapping program to elucidate the many relationships that exist amongst the current standards. In this work, flammability test requirements for public transportation seating are studied, with a major emphasis on seating for railway applications. Requirements for seating in aviation, automotive (both cars and buses) and military vehicles are included in the discussion for comparative purposes. Fire is a complex phenomenon that is difficult to characterize. The legislated testing protocols reflect this complexity with some geographic jurisdictions mandating as many as six different types of fire testing for rail seating. This work looks in depth at two of the main types of fire testing: flame spread testing and toxic effluent testing. Flame spread testing was chosen because it is widely required, and toxic effluent testing was chosen because of the many complexities and ambiguities present amongst these standards. Eleven flame-spread tests are compared on a semi-quantitative basis, and eight fire effluent toxicity tests are discussed on a qualitative basis. The technique developed was useful to elucidate the relationships, similarities and differences amongst the fire safety requirements for transportation seating. There are large differences in requirements among transportation sectors as well as on a geographical basis. Using this technique, it was possible to categorize the flame spread tests into two groups and to compare the relative intensity of the tests within each of these subsets. The fire effluent toxicity tests varied so much in approach that only qualitative comparisons were possible.

In recent decades, many manufacturing industries have globalized their operations and the Canadian manufacturing sector has experienced dramatic downsizing. For a manufacturing company to succeed therefore, it is necessary for them to operate with a global perspective. In the area of fire safety, this requires understanding of, and compliance with, global regulatory requirements. This research develops a systematic approach that can be utilized to analyze and compare the complex fire safety regulatory requirements that are stipulated for a selected topic in various countries. The approach developed is sufficiently general that it can be leveraged to compare and contrast global standards in any field or discipline. The methodology outlines six aspects of the regulatory environment that must be considered in sorting standards and then uses spreadsheets and a mind mapping program to elucidate the many relationships that exist amongst the current standards. In this work, flammability test requirements for public transportation seating are studied, with a major emphasis on seating for railway applications. Requirements for seating in aviation, automotive (both cars and buses) and military vehicles are included in the discussion for comparative purposes. Fire is a complex phenomenon that is difficult to characterize. The legislated testing protocols reflect this complexity with some geographic jurisdictions mandating as many as six different types of fire testing for rail seating. This work looks in depth at two of the main types of fire testing: flame spread testing and toxic effluent testing. Flame spread testing was chosen because it is widely required, and toxic effluent testing was chosen because of the many complexities and ambiguities present amongst these standards. Eleven flame-spread tests are compared on a semi-quantitative basis, and eight fire effluent toxicity tests are discussed on a qualitative basis. The technique developed was useful to elucidate the relationships, similarities and differences amongst the fire safety requirements for transportation seating. There are large differences in requirements among transportation sectors as well as on a geographical basis. Using this technique, it was possible to categorize the flame spread tests into two groups and to compare the relative intensity of the tests within each of these subsets. The fire effluent toxicity tests varied so much in approach that only qualitative comparisons were possible.

It is critical for the construction industry to ensure that new building designs and materials, including wall and floor assemblies, provide an acceptable level of fire safety. A key fire safety requirement that is specified in building codes is the minimum fire resistance rating. A manufacturer of building materials (e.g., insulation or drywall) is currently required to perform full-scale fire furnace tests in order to determine the fire resistance ratings of assemblies that use their products. Due to the cost of these tests, and the limited number of test facilities, it can be difficult to properly assess the impact of changes to individual components on the overall fire performance of an assembly during the design process. It would be advantageous to be able to use small-scale fire tests for this purpose, as these tests are relatively inexpensive to perform. One challenge in using results of small-scale fire tests to predict full-scale fire performance is the difficulty in truly representing a larger product or assembly using a small-scale test specimen. Another challenge is the lack of established methods of scaling fire test results. Cone calorimeter tests were used to measure heat transfer through small-scale specimens that are representative of generic wall assemblies for which fire resistance ratings are given in the National Building Code of Canada. Test specimens had a surface area of 111.1 mm (4.375 in.) by 111.1 mm (4.375 in.), and consisted of single or double layers of gypsum board, stone wool insulation and spruce-pine-fir (SPR) studs. As the specimens were designed to represent a one-quarter scale model of a common wall design, with studs spaced at a centre-to-centre distance of 406.4 mm (16 in.), the wood studs were made by cutting nominal 2x4 studs (38 mm by 89 mm) into 9.25 mm by 89 mm (0.375 in. by 3.5 in.) pieces. The scaled studs were then spaced at a centre-to-centre distance of 101.6 mm (4 in.). Three types of gypsum board were tested: 12.7 mm (0.5 in.) regular and lightweight gypsum board, and 15.9 mm (0.625 in.) type X gypsum board. Temperature measurements were made at various points within the specimens during 70 min exposures to an incident heat flux of 35, 50 and 75 kW/m2 using 24 AWG Type K thermocouples and an infrared thermometer. Temperature measurements made during cone calorimeter tests were compared with temperature measurements made during fire resistance tests of the same generic assemblies and the result show a very good agreement for the first 25 min of testing at the unexposed side. A one-dimensional conduction heat transfer model was developed using the finite difference method in order to predict temperatures within the small-scale wall assemblies during the cone calorimeter tests. Constant and temperature-dependent thermal properties were used in the model, in order to study the effects of changes to materials and thermal properties on fire performance. A comparison of predicted and measured temperatures during the cone calorimeter tests of the generic wall assemblies is presented in this thesis. The model had varying degrees of success in predicting temperature profiles obtained in the cone calorimeter tests. Predicted and measured times for temperatures to reach 100C and 250C on the unexposed side of the gypsum board layer closest to the cone heater were generally within 10%. There was less agreement between predicted and measured times to reach 600C at this location, and the temperature increase on the unexposed side of the test specimen. The model did not do a good job in predicting temperatures in the insulated double layer walls. Sensitivity studies show that the thermal conductivity of the gypsum board has the most significant impact on the predicted temperature.

"This paper investigates the thermal conditions at the surface and at depth of 1.8 cm (3/4-inch) maple plywood exposed to heat fluxes between 6 and 15 kW/m2 in the cone calorimeter for up to 8 hours. The minimum heat flux for unpiloted smoldering ignition was 7.5 kW/m2 and compared favorably to classical self-heating theory. The role of self-heating was explored via temperature measurements distributed within the specimens. Elevated subsurface temperature profiles indicated self-heating was an important ignition factor resulting in ignition at depth with smolder propagation to the surface and into the material. The ignition depth was shown to be a function of the heat flux with the depth moving towards the surface as the heat flux increased. Supporting work included sensor calibration testing, mass loss rate analysis, char depth testing and computer modeling. The calibration testing showed optical pyrometer temperature measurements compare favorably to those of surface mounted thermocouples. Mass loss rate analysis was found to be a lagging indicator of smoldering ignition. The char depth tests showed that the rate of change of the temperatures recorded at depth increased around the time the derived char front passed. Computer modeling (HEATING) of a heat flux applied to the plywood for conditions similar to the performed ignition tests compared favorably to experimental data for sub-critical incident heat flux temperature profiles, excepting surface temperatures. For heat fluxes near critical, the model correctly predicted thermal runaway below the sample surface. At higher heat fluxes simulation results indicated surface ignition at times significantly earlier than experimental results."

An accumulated combustible dust layer on some hot process equipment such as dryers or hot bearings can be ignited and result in fires when the hot surface temperature is sufficiently high. The ASTM E 2021 test procedure is often used to determine the Hot Surface Minimum Ignition Temperature for a half inch deep layer of a particular dust material. This test procedure was used in this thesis to study possible effects of combustible liquid (such as lubricating oil) and powder additives in the dust layer as well as air flow effects. The following combustible dusts were used: paper dust from a printing press, Arabic gum powder, Pittsburgh seam coal, and brass powder. To develop an improved understanding of the heat transfer, and oxygen mass transfer phenomena occurring in the dust layer, additional instrumentation such as a second thermocouple in the dust layer, an oxygen analyzer and gas sampling line, and an air velocity probe were used in at least some tests. Hot Surface Minimum Ignition temperatures were 220oC for Pittsburgh seam coal, 360oC for paper dust, 270¡Ãƒâ€° for Arabic gum powder, and > 400oC for brass powder. The addition of 5-10 weight percent stearic acid powder resulted in significantly lower ignition temperature of brass powder. When combustible liquids were added to the dust layer, the ignition temperatures did not decrease regardless of the liquids¡¯ ignitibility because the liquids seemed to act as heat absorbents. Although air velocity on the order of 1 cm/s did not affect test results, much larger air velocities did affect the results. With 33 cm/s downward airflow at the elevation of the surface of the layer, Pittsburgh seam coal was not ignited at 230¡Ãƒâ€° which was 10¡Ãƒâ€° higher than the 220¡Ãƒâ€° hot surface ignition temperature without airflow. Based on the results and data from the additional instrumentations, modifications of the ASTM E2021 test procedure are recommended.