Charring rates and temperature profiles of wood sections

Frangi, Andréa; Fontana, Mario

doi:10.1002/fam.819

Cited by 114 publications

(122 citation statements)

References 1 publication

Supporting

Mentioning

112

Contrasting

Unclassified

Order By: Relevance

“…8, significantly affects both the out-of-plane deflections and time-to-failure predictions. The sensitivity of the time-to-failure predictions to the residual elastic modulus was determined by comparing the predicted and observed times-to-failure for all intermediate-scale tests performed by Summers [21]. The results are similar to that shown in Fig.…”

Section: Sensitivity Of Model Predictionssupporting

confidence: 72%

“…This concept may be applied to FRP laminates, though, as for timber, the heat flux and convective conditions will affect the charring rate [21]. Mouritz and Mathys [22] determined that the rate of growth of the char layer thickness is non-constant over time and is dependent on both the exposure time and applied heat flux for FRP laminates.…”

Section: Thermal Model Developmentmentioning

confidence: 99%

See 1 more Smart Citation

Sensitivity Analysis of a Thermo-Structural Model for Materials in Fire

Summers¹,

Lattimer²,

Case³

et al. 2011

Fire Safety Science - Proceedings of the 10th International Sym

View full text Add to dashboard Cite

A new thermo-structural model was developed and validated to predict the failure of compressively loaded fiber-reinforced polymer (FRP) laminates during one-sided heating from a fire. The model consists of the best thermal and structural models in the literature integrated into a single predictive model. This includes a one-dimensional pyrolysis model to predict the thermal response of a decomposing material. Using the thermal response to calculate the mechanical properties, an integral structural model was developed considering thermally-induced bending caused by one-sided heating. The thermo-structural model predicts out-of-plane deflections and compressive failure of laminates in fire conditions. This paper also provides an improved failure model for FRP laminates exposed to fire, a first validation study on the modeling approach using intermediate-scale compression load failure tests with a one-side heat flux exposure, and a first sensitivity study of the input parameter effects on the structural response of FRP laminates. Through the sensitivity study, the out-of-plane deflection predictions exhibited little sensitivity to the thermal inputs. However, the time-to-failure predictions were significantly affected by the virgin conductivity and specific heat capacity. The structural inputs exhibited a significant impact on the out-of-plane deflection predictions. The in-plane thermal expansion, residual elastic modulus above the glass transition temperature, and vertical temperature profile significantly affected the magnitude of the out-of-plane deflection; however, only the in-plane thermal expansion and residual elastic modulus affected the failure direction. The time-to-failure prediction was only significantly affected by the residual elastic modulus. A better agreement between the predicted and observed times-to-failure was achieved by reducing the residual elastic modulus.KEYWORDS: sensitivity, thermo-structural, modeling, composites, FRP laminate. NOMENCLATURE LISTING

show abstract

Section: Sensitivity Of Model Predictionssupporting

confidence: 72%

Section: Thermal Model Developmentmentioning

confidence: 99%

Sensitivity Analysis of a Thermo-Structural Model for Materials in Fire

Summers¹,

Lattimer²,

Case³

et al. 2011

Fire Safety Science - Proceedings of the 10th International Sym

View full text Add to dashboard Cite

show abstract

“…The char layer is a good insulator and protects the remaining uncharred residual cross-section against heat. For timber surfaces unprotected throughout the time of fire exposure, the charring rate can be assumed constant with time [4]. As a basic value, the one-dimensional charring rate β 0 is usually taken as the value observed for one-dimensional heat transfer under ISO-fire exposure in a semi-infinite timber slab.…”

Section: Charring Of Timbermentioning

confidence: 99%

Fire behaviour of cross-laminated solid timber panels

Frangi¹,

Fontana²,

Knobloch³

et al. 2008

Fire Saf. Sci.

View full text Add to dashboard Cite

Cross-laminated solid timber panels represent an interesting technical and economical product for modern timber structures. The use of large prefabricated cross-laminated solid timber panels for load-bearing wall and floor assemblies has become increasingly popular in particular for residential timber buildings. The fire behaviour of cross-laminated solid timber panels has been experimentally and numerically studied during two different ongoing research projects carried out at the Institute of Structural Engineering of ETH Zurich, Switzerland and the Trees and Timber Institute CNR-IVALSA in Trento, Italy. The paper presents the main results of the experimental and numerical analyses. Particular attention is given to the comparison of the fire behaviour of cross-laminated solid timber panels with homogeneous timber panels.The results of the analysis have shown that the fire behaviour of cross-laminated solid timber panels depends on the behaviour of the single layers. If the charred layers fall off, an increased charring rate needs to be taken into account. The same effect is observed for initially protected timber members after the fire protection has fallen off. Thus the fire behaviour of cross-laminated solid timber panels can be strongly influenced by the thickness and the number of layers. Further vertical structural members (walls) may show a better fire behaviour in comparison to horizontal members (slabs).

show abstract

“…The same effects were observed for connections D1.3 and D1.4 protected by timber boards and gypsum plasterboards, respectively. The analysis of the residual cross-sections of all test specimens showed that the charring depth measured in section A-A (located close to the connection) corresponded to a charring rate of about 0.7 mm/min on all four sides and agrees well with values measured in several experimental studies [18][19][20]. The charring depth measured in section B-B (located in the connection) corresponded to a charring rate varying between 0.8 and 0.9 mm/min on the top and bottom and between 1.0 and 1.2 mm/ min on the sides.…”

Section: Residual Cross-sectionmentioning

confidence: 67%

Experimental fire analysis of steel‐to‐timber connections using dowels and nails

2009

Self Cite

View full text Add to dashboard Cite

SUMMARYThe paper describes and discusses the results of an extensive testing programme on the structural behaviour of timber connections under ISO-fire. The results of reference tests performed at normal temperature are also presented. From the variety of timber connections multiple shear steel-to-timber connections with dowels and slotted-in steel plates and connections with steel side plates and annular ringed shank nails were experimentally studied. Particular attention was given to the analysis of the efficiency of different strategies in order to increase the fire resistance of the timber connections. The test results showed that unprotected multiple shear steel-to-timber connections with dowels designed for normal temperature reached a fire resistance of about 30 min. A reduction of the load level applied during the fire did not lead to a significant increase of the fire resistance. By increasing the side timber members as well as the end distance of the dowels by 40 mm the connections reached a fire resistance of more than 70 min. Connections protected by timber boards or gypsum plasterboards showed a fire resistance of around 60 min. Thus, from a fire design point of view these strategies were favourable in order to increase the fire resistance of the connections significantly. Unprotected connections with steel side plates and annular ringed shank nails failed already after about 12 min due to large deformations of the nails and the steel side plates directly exposed to fire. By protecting the steel side plates using an intumescent paint the fire resistance of the connections was increased to around 30 min. The test results enlarged the experimental background of timber connections in fire significantly.

show abstract

Charring rates and temperature profiles of wood sections

Cited by 114 publications

References 1 publication

Sensitivity Analysis of a Thermo-Structural Model for Materials in Fire

Sensitivity Analysis of a Thermo-Structural Model for Materials in Fire

Fire behaviour of cross-laminated solid timber panels

Experimental fire analysis of steel‐to‐timber connections using dowels and nails

Contact Info

Product

Resources

About