@article{schlotzhauer_critical_2020,
	title = {Critical discussion of perpendicular to grain tension testing of structural timber – case study on the {European} hardwoods ash, beech and maple},
	volume = {15},
	issn = {1748-0272},
	url = {https://doi.org/10.1080/17480272.2019.1596157},
	doi = {10.1080/17480272.2019.1596157},
	abstract = {Knowledge about perpendicular to grain tension behavior of wood is essential, since in construction tension stresses perpendicular to grain cannot be avoided completely. Especially for hardwoods, the data basis is scarce. EN 338 design values are with 0.6 N/mm² characteristic strength set very low. The US-American National Design Specifications even set this value to zero and make local reinforcements mandatory. This paper compares strength and stiffness values attained with newly-designed, little, prismatic specimens and EN 408 structural timber specimens to evaluate the current European design values. Little specimen’s characteristic strength values range from 7.2 to 10.6 N/mm² and are assumed to be real material properties. EN 408 specimen values are with approximately 4.0 N/mm² lower. These lower values are mainly due to stress peaks introduced by the force introduction. Strength values attained for the medium-dense European hardwoods beech, ash and maple exceed EN 338 design values by a factor of six to seven. Adaptation of the EN 338 design value is not recommended, though. The abundance of influencing factors makes clear that the design value and the ensuing design code have to be synchronized carefully by tedious testing in order to make use of the perpendicular to grain tension strength potential of the selected hardwoods.},
	number = {5},
	urldate = {2020-08-24},
	journal = {Wood Material Science \& Engineering},
	author = {Schlotzhauer, Philipp and Ehrmann, Alexander and Bollmus, Susanne and Militz, Holger},
	month = sep,
	year = {2020},
	note = {Publisher: Taylor \& Francis
\_eprint: https://doi.org/10.1080/17480272.2019.1596157},
	keywords = {strength, stiffness, design value, EN 338, Hardwoods, perpendicular to grain, tension, test set-up},
	pages = {278--288},
	file = {Full Text PDF:/home/maicher/Zotero/storage/H385PSKF/Schlotzhauer et al. - 2020 - Critical discussion of perpendicular to grain tens.pdf:application/pdf;Snapshot:/home/maicher/Zotero/storage/2A9W9FZD/17480272.2019.html:text/html},
}

Knowledge about perpendicular to grain tension behavior of wood is essential, since in construction tension stresses perpendicular to grain cannot be avoided completely. Especially for hardwoods, the data basis is scarce. EN 338 design values are with 0.6 N/mm² characteristic strength set very low. The US-American National Design Specifications even set this value to zero and make local reinforcements mandatory. This paper compares strength and stiffness values attained with newly-designed, little, prismatic specimens and EN 408 structural timber specimens to evaluate the current European design values. Little specimen’s characteristic strength values range from 7.2 to 10.6 N/mm² and are assumed to be real material properties. EN 408 specimen values are with approximately 4.0 N/mm² lower. These lower values are mainly due to stress peaks introduced by the force introduction. Strength values attained for the medium-dense European hardwoods beech, ash and maple exceed EN 338 design values by a factor of six to seven. Adaptation of the EN 338 design value is not recommended, though. The abundance of influencing factors makes clear that the design value and the ensuing design code have to be synchronized carefully by tedious testing in order to make use of the perpendicular to grain tension strength potential of the selected hardwoods.

@article{hermann_breaking_2020,
	title = {Breaking {News}! {Making} and testing {Bronze} {Age} balance scales},
	volume = {32},
	issn = {2352409X},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S2352409X20302352},
	doi = {10.1016/j.jasrep.2020.102444},
	abstract = {This interdisciplinary paper (archaeology, macromolecular chemistry and material science) investigates the production and load-bearing capacities of Bronze Age balance scales. The existence of weighing equipment and practices in Late Bronze Age Europe has been proven beyond doubt. Although hundreds of balance weights from Central and Western Europe have recently been identified in the archaeological record, balance scales are still extremely rare. Consisting of balance beams, suspension cords, scale pans and sometimes metal suspension loops, the only evidence found to date are 18 complete and fragmented balance beams. Made of bone or antler, these balance beams are often perceived as extremely fragile and only able to weigh-out minute loads. This, however, had never been tested. In order to understand exactly how Bronze Age balances were made, of what materials and how much load they could bear, a number of replica balance beams, suspension cords and metal loops were created. The load-bearing capacity was then tested with two standard material sciences testing methods: three-point bending tests and uniaxial tensile testing.},
	language = {en},
	urldate = {2020-06-24},
	journal = {Journal of Archaeological Science: Reports},
	author = {Hermann, Raphael and Steinhoff, Judith and Schlotzhauer, Philipp and Vana, Philipp},
	month = aug,
	year = {2020},
	pages = {102444},
	file = {Hermann et al. - 2020 - Breaking News! Making and testing Bronze Age balan.pdf:/home/maicher/Zotero/storage/73NLSA88/Hermann et al. - 2020 - Breaking News! Making and testing Bronze Age balan.pdf:application/pdf},
}

This interdisciplinary paper (archaeology, macromolecular chemistry and material science) investigates the production and load-bearing capacities of Bronze Age balance scales. The existence of weighing equipment and practices in Late Bronze Age Europe has been proven beyond doubt. Although hundreds of balance weights from Central and Western Europe have recently been identified in the archaeological record, balance scales are still extremely rare. Consisting of balance beams, suspension cords, scale pans and sometimes metal suspension loops, the only evidence found to date are 18 complete and fragmented balance beams. Made of bone or antler, these balance beams are often perceived as extremely fragile and only able to weigh-out minute loads. This, however, had never been tested. In order to understand exactly how Bronze Age balances were made, of what materials and how much load they could bear, a number of replica balance beams, suspension cords and metal loops were created. The load-bearing capacity was then tested with two standard material sciences testing methods: three-point bending tests and uniaxial tensile testing.

@phdthesis{schlotzhauer_strength_2019,
	address = {Göttingen},
	type = {Dissertation},
	title = {Strength grading and selected strength properties of {European} hardwoods},
	url = {https://ediss.uni-goettingen.de/handle/21.11130/00-1735-0000-0003-C16E-8},
	abstract = {Since national standing stocks of hardwoods will be rising in central Europe in the future, it is the declared political will to introduce these resources to a higher extent into the building sector. That is why since the turn of the century more and more funds for hardwood research have been made available. This research together with efforts made by private companies has led to a number of European and German technical approvals for hardwood glulam (oak, beech, sweet chestnut, beech LVL). A further result was the inclusion of the hardwood species beech, oak, maple, ash and poplar into the European standard EN 1912, which allows the use of these hardwoods as solid wood product in construction. Nonetheless, a wide-spread use of these products cannot be witnessed at present. One goal of this dissertation was to identify reasons for this development. Next to market driven causes like a still sufficient availability of softwood and high prices of hardwood products, technological reasons (problems) regarding hardwood glulam and solid wood were identified. In the course of this dissertation, it was aimed to answer some of these technical questions, in order to work towards a more reliable and cost reduced (etc.) hardwood construction product. First, the market and standard situation was identified and put together. The subsequent research was designed to create answers to pressing questions connected to the work field of strength grading. Here, a raised improvement potential was seen. For the six European hardwood species oak, beech, ash, maple, lime and birch the distribution of sawn wood characteristics (of a typical, market available assortment) were determined and the timber availability examined, in order to evaluate the suitability of the species for a wider use in construction. For the species ash and maple, a yield analysis from round wood sections to sorted glulam lamellas was carried out, which pointed out the need for an improved sawing technique (incl. sawing pattern), a faster drying technology and optimized strength grading. When it comes to strength grading, the grain angle is highly correlated with the final tensile strength of the glulam lamella. According to experts on the field, it is not possible to determine the grain angle on hardwoods in a non-destructive way. In the course of this dissertation, it was proven that for five of the six above-mentioned hardwood species (except ash) it is possible to determine the grain angles by machine use. Also, in this field of work falls the topic “size effect”, which was examined for bending, tension and compression parallel to grain (for all six species). Mechanical properties in tension and compression testing perpendicular to grain were examined for ash, maple and beech construction timber. In addition, tension tests on glulam lamellas were carried out and the results correlated with the sorting results. These experiments revealed the unused potentials (in standard strength values) of some of the hardwoods, but also pointed out the difficulties in raising the final yield (i.e. lower production costs).},
	language = {Englisch},
	school = {Georg-August-Universität Göttingen},
	author = {Schlotzhauer, Philipp},
	year = {2019},
	file = {Schlotzhauer - 2019 - Strength grading and selected strength properties .pdf:/home/maicher/Zotero/storage/T3RA245F/Schlotzhauer - 2019 - Strength grading and selected strength properties .pdf:application/pdf},
}

Since national standing stocks of hardwoods will be rising in central Europe in the future, it is the declared political will to introduce these resources to a higher extent into the building sector. That is why since the turn of the century more and more funds for hardwood research have been made available. This research together with efforts made by private companies has led to a number of European and German technical approvals for hardwood glulam (oak, beech, sweet chestnut, beech LVL). A further result was the inclusion of the hardwood species beech, oak, maple, ash and poplar into the European standard EN 1912, which allows the use of these hardwoods as solid wood product in construction. Nonetheless, a wide-spread use of these products cannot be witnessed at present. One goal of this dissertation was to identify reasons for this development. Next to market driven causes like a still sufficient availability of softwood and high prices of hardwood products, technological reasons (problems) regarding hardwood glulam and solid wood were identified. In the course of this dissertation, it was aimed to answer some of these technical questions, in order to work towards a more reliable and cost reduced (etc.) hardwood construction product. First, the market and standard situation was identified and put together. The subsequent research was designed to create answers to pressing questions connected to the work field of strength grading. Here, a raised improvement potential was seen. For the six European hardwood species oak, beech, ash, maple, lime and birch the distribution of sawn wood characteristics (of a typical, market available assortment) were determined and the timber availability examined, in order to evaluate the suitability of the species for a wider use in construction. For the species ash and maple, a yield analysis from round wood sections to sorted glulam lamellas was carried out, which pointed out the need for an improved sawing technique (incl. sawing pattern), a faster drying technology and optimized strength grading. When it comes to strength grading, the grain angle is highly correlated with the final tensile strength of the glulam lamella. According to experts on the field, it is not possible to determine the grain angle on hardwoods in a non-destructive way. In the course of this dissertation, it was proven that for five of the six above-mentioned hardwood species (except ash) it is possible to determine the grain angles by machine use. Also, in this field of work falls the topic “size effect”, which was examined for bending, tension and compression parallel to grain (for all six species). Mechanical properties in tension and compression testing perpendicular to grain were examined for ash, maple and beech construction timber. In addition, tension tests on glulam lamellas were carried out and the results correlated with the sorting results. These experiments revealed the unused potentials (in standard strength values) of some of the hardwoods, but also pointed out the difficulties in raising the final yield (i.e. lower production costs).

@article{kovryga_visual_2019,
	title = {Visual and machine strength grading of {European} ash and maple for glulam application},
	volume = {73},
	issn = {1437-434X, 0018-3830},
	url = {http://www.degruyter.com/view/j/hfsg.ahead-of-print/hf-2018-0142/hf-2018-0142.xml},
	doi = {10.1515/hf-2018-0142},
	number = {8},
	urldate = {2019-03-25},
	journal = {Holzforschung},
	author = {Kovryga, Andriy and Schlotzhauer, Philipp and Stapel, Peter and Militz, Holger and van de Kuilen, Jan-Willem G.},
	month = jul,
	year = {2019},
	pages = {773--787},
	file = {Kovryga et al. - 2019 - Visual and machine strength grading of European as.pdf:/home/maicher/Zotero/storage/C9S7IPDD/Kovryga et al. - 2019 - Visual and machine strength grading of European as.pdf:application/pdf},
}

@article{schlotzhauer_analysis_2019,
	title = {Analysis of {Economic} {Feasibility} of {Ash} and {Maple} {Lamella} {Production} for {Glued} {Laminated} {Timber}},
	volume = {10},
	copyright = {http://creativecommons.org/licenses/by/3.0/},
	url = {https://www.mdpi.com/1999-4907/10/7/529},
	doi = {10.3390/f10070529},
	abstract = {Background and Objectives: In the near future, in Europe a raised availability of hardwoods is expected. One possible sales market is the building sector, where medium dense European hardwoods could be used as load bearing elements. For the hardwood species beech, oak, and sweet chestnut technical building approvals already allow the production of hardwood glulam. For the species maple and ash this is not possible yet. This paper aims to evaluate the economic feasibility of glulam production from low dimension ash and maple timber from thinnings. Therefore, round wood qualities and the resulting lumber qualities are assessed and final as well as intermediate yields are calculated. Materials and Methods: 81 maple logs and 79 ash logs cut from trees from thinning operations in mixed (beech) forest stands were visually graded, cant sawn, and turned into strength-graded glulam lamellas. The volume yield of each production step was calculated. Results: The highest volume yield losses occur during milling of round wood (around 50\%) and \“presorting and planning\” the dried lumber (56\–60\%). Strength grading is another key process in the production process. When grading according to DIN 4074-5 (2008), another 40\–50\% volume loss is reported, while combined visual and machine grading only produces 7\–15\% rejects. Conclusions: Yield raise potentials were identified especially in the production steps milling, presorting and planning and strength grading.},
	language = {en},
	number = {7},
	urldate = {2019-06-26},
	journal = {Forests},
	author = {Schlotzhauer, Philipp and Kovryga, Andriy and Emmerich, Lukas and Bollmus, Susanne and Van de Kuilen, Jan-Willem and Militz, Holger},
	month = jul,
	year = {2019},
	keywords = {European hardwoods, glulam, low quality round wood, strength grading, volume yield},
	pages = {529},
	file = {Full Text PDF:/home/maicher/Zotero/storage/A4HRNTQP/Schlotzhauer et al. - 2019 - Analysis of Economic Feasibility of Ash and Maple .pdf:application/pdf;Snapshot:/home/maicher/Zotero/storage/VH2KH8NV/529.html:text/html},
}

Background and Objectives: In the near future, in Europe a raised availability of hardwoods is expected. One possible sales market is the building sector, where medium dense European hardwoods could be used as load bearing elements. For the hardwood species beech, oak, and sweet chestnut technical building approvals already allow the production of hardwood glulam. For the species maple and ash this is not possible yet. This paper aims to evaluate the economic feasibility of glulam production from low dimension ash and maple timber from thinnings. Therefore, round wood qualities and the resulting lumber qualities are assessed and final as well as intermediate yields are calculated. Materials and Methods: 81 maple logs and 79 ash logs cut from trees from thinning operations in mixed (beech) forest stands were visually graded, cant sawn, and turned into strength-graded glulam lamellas. The volume yield of each production step was calculated. Results: The highest volume yield losses occur during milling of round wood (around 50%) and “presorting and planning” the dried lumber (56–60%). Strength grading is another key process in the production process. When grading according to DIN 4074-5 (2008), another 40–50% volume loss is reported, while combined visual and machine grading only produces 7–15% rejects. Conclusions: Yield raise potentials were identified especially in the production steps milling, presorting and planning and strength grading.

@article{schlotzhauer_comparison_2018,
	title = {Comparison of three systems for automatic grain angle determination on {European} hardwood for construction use},
	issn = {0018-3768, 1436-736X},
	url = {http://link.springer.com/10.1007/s00107-018-1286-z},
	doi = {10.1007/s00107-018-1286-z},
	language = {en},
	urldate = {2018-01-24},
	journal = {European Journal of Wood and Wood Products},
	author = {Schlotzhauer, Philipp and Wilhelms, Fritz and Lux, Christian and Bollmus, Susanne},
	month = jan,
	year = {2018},
	file = {Schlotzhauer (2018) Comparison of three systems for automatic grain angle determination on European hardwood for construction use.pdf:/home/maicher/Zotero/storage/KSNR8RV3/Schlotzhauer (2018) Comparison of three systems for automatic grain angle determination on European hardwood for construction use.pdf:application/pdf},
}

@inproceedings{schlotzhauer_strength_2018,
	address = {Sopron, Hungary},
	title = {Strength grading of hardwood structural timber},
	volume = {8},
	language = {English},
	booktitle = {8th {Hardwood} {Conference}},
	author = {Schlotzhauer, Philipp and Bollmus, Susanne, Bollmus and Militz, Holger},
	year = {2018},
	pages = {166--167},
	file = {Schlotzhauer - Strength grading of hardwood structural timber.pdf:/home/maicher/Zotero/storage/TNTFCPC7/Schlotzhauer - Strength grading of hardwood structural timber.pdf:application/pdf},
}

@misc{schlotzhauer_strength_2018-1,
	address = {Sopron, Hungary},
	type = {Presentation},
	title = {Strength grading of hardwood structural timber},
	language = {English},
	author = {Schlotzhauer, Philipp},
	month = oct,
	year = {2018},
	file = {Schlotzhauer - 2018 - Strength grading of hardwood structural timber.pdf:/home/maicher/Zotero/storage/54EWWGH3/Schlotzhauer - 2018 - Strength grading of hardwood structural timber.pdf:application/pdf},
}

@inproceedings{schlotzhauer_geringwertiges_2018,
	address = {Göttingen},
	title = {Geringwertiges {Laubholz} - {Konstruktiv} einsetzbar?},
	author = {Schlotzhauer, Philipp},
	year = {2018},
	pages = {215},
	file = {FowiTa 2018_Abstact_Schlotzhauer_Geringwertiges Laubholz - Konstruktiv einsetzbar_Seite 215.pdf:/home/maicher/Zotero/storage/X5HUQDLZ/FowiTa 2018_Abstact_Schlotzhauer_Geringwertiges Laubholz - Konstruktiv einsetzbar_Seite 215.pdf:application/pdf;Schlotzhauer - Geringwertiges Laubholz - Konstruktiv einsetzbar.pdf:/home/maicher/Zotero/storage/WUUTQHD9/Schlotzhauer - Geringwertiges Laubholz - Konstruktiv einsetzbar.pdf:application/pdf},
}

@article{schlotzhauer_visual_2018,
	title = {Visual and machine strength grading characteristics of six {European} hardwoods},
	volume = {61},
	language = {English},
	number = {6},
	journal = {Holztechnologie},
	author = {Schlotzhauer, Philipp and Bollmus, Susanne and Militz, Holger},
	year = {2018},
	pages = {5--14},
	file = {Schlotzhauer et al. - 2018 - Visual and machine strength grading characteristic.pdf:/home/maicher/Zotero/storage/QHWICRKZ/Schlotzhauer et al. - 2018 - Visual and machine strength grading characteristic.pdf:application/pdf},
}

@article{schlotzhauer_effect_2017,
	title = {Effect of size and geometry on strength values and {MOE} of selected hardwood species},
	volume = {12},
	issn = {1748-0272, 1748-0280},
	url = {https://www.tandfonline.com/doi/full/10.1080/17480272.2015.1073175},
	doi = {10.1080/17480272.2015.1073175},
	language = {en},
	number = {3},
	urldate = {2017-04-18},
	journal = {Wood Material Science \& Engineering},
	author = {Schlotzhauer, P. and Nelis, P. A. and Bollmus, S. and Gellerich, A. and Militz, H. and Seim, W.},
	month = may,
	year = {2017},
	pages = {149--157},
	file = {Schlotzhauer (2017) Effect of size and geometry on strength values and MOE of selected hardwood species.pdf:/home/maicher/Zotero/storage/XM9JRXMX/Schlotzhauer (2017) Effect of size and geometry on strength values and MOE of selected hardwood species.pdf:application/pdf},
}

@incollection{schlotzhauer_capitulo_2017,
	address = {Puyo, Ecuador},
	title = {Capítulo 8 - {Análisis} de la cadena de producción y comercialización de madera en pequeños productores de la {Amazonía} {Ecuatoriana}},
	language = {Spanish},
	booktitle = {Gente, {Bosque} y {Biodiversidad}: {El} rol del bosque sobre la biodiversidad y las poblaciones {ruralesEdition}: {PrimeraChapter}: {8Publisher}: {Editors}: {Bolier} {Torres}, {Julio} {C}. {Vargas}, {Yasiel} {Arteaga}, {Alexandra} {Torres}, pablo {Lozano}},
	publisher = {Universidad Estatal Amazónica},
	author = {Schlotzhauer, Philipp and Torres, Bolier},
	editor = {Torres, B. and Vargas, J.C. and Arteaga, Y. and Torres, A. and Lozano, P.},
	year = {2017},
	pages = {253},
}

@techreport{emmerich_untersuchungen_2016,
	address = {Göttingen},
	type = {Projektarbeit},
	title = {Untersuchungen zur {Schnittholzausbeute} von {Ahorn}- und {Eschenlangholzabschnitten} zur {Bereitstellung} von {Rohlamellen} für die {Produktion} von {Brettschichtholz}},
	language = {de},
	institution = {Georg-August-Universität Göttingen, Fakultät für Forstwissenschaften und Waldökologie, Abteilung Holzbiologie und Holzprodukte},
	author = {Emmerich, Lukas},
	year = {2016},
	note = {Prüfer: Prof. Dr. Holger Militz
Betreuung: Dr. Susanne Bollmus
                   M.Sc. Philipp Schlotzhauer},
	file = {Emmerich - 2016 - Untersuchungen zur Schnittholzausbeute von Ahorn- .pdf:/home/maicher/Zotero/storage/K2ZN89NW/Emmerich - 2016 - Untersuchungen zur Schnittholzausbeute von Ahorn- .pdf:application/pdf},
}

@techreport{wingen_uberprufung_2016,
	address = {Göttingen},
	type = {Masterarbeit},
	title = {Überprüfung normativer {Eigenschaften} von {Laubholz} für tragende {Zwecke} / {Evaluation} of standard values of hardwood for structural applications},
	language = {de},
	institution = {Georg-August-Universität Göttingen, Fakultät für Forstwissenschaften und Waldökologie, Abteilung Holzbiologie und Holzprodukte},
	author = {Wingen, Benedikt},
	year = {2016},
	note = {Prüfer und Betreuer:
Dr. Hannes Schwager
Dr. Antje Gellerich
Philipp Schlotzhauer},
	file = {Wingen - 2016 - Überprüfung normativer Eigenschaften von Laubholz .pdf:/home/maicher/Zotero/storage/VCMZTT5L/Wingen - 2016 - Überprüfung normativer Eigenschaften von Laubholz .pdf:application/pdf},
}

@inproceedings{schlotzhauer_uberprufung_2016,
	address = {Stuttgart},
	title = {Überprüfung der in {DIN} {EN} 338 angegeben {Festigkeits}- und {Steifigkeitseigenschaften} sowie {Rohdichten} für {Buchen}-, {Eschen}- und {Ahornholz}},
	author = {Schlotzhauer, Philipp},
	year = {2016},
}

@inproceedings{schlotzhauer_machine_2016,
	address = {Vienna},
	title = {Machine grain angle determination on spruce, beech and oak lumber for construction use},
	author = {Schlotzhauer, Philipp and Wilhelms, Fritz and Lux, Christian and Bollmus, Susanne},
	year = {2016},
}

@inproceedings{nemeth_machine_2014,
	title = {Machine grain angle determination on six {European} hardwoods},
	shorttitle = {Machine grain angle determination on six {European} hardwoods},
	author = {Schlotzhauer, P. and Emmerich, L. and Militz, H. and Bollmus, S.},
	editor = {Németh, R. and Teischinger, A. and Schmitt, U.},
	year = {2014},
	pages = {45--46},
	file = {Proceedings_Eco-efficient Resource Wood_2014_Sopron_Vienna_final:/home/maicher/Zotero/storage/MITT2ZZF/Proceedings_Eco-efficient Resource Wood_2014_Sopron_Vienna_final.pdf:application/pdf},
}

@inproceedings{schlotzhauer_effect_2014,
	title = {Effect of size on tensile, compression and bending  strengths of six {European} hardwood species},
	author = {Schlotzhauer, Philipp and Nelis, Philipp Alexander and Militz, Holger and Bollmus, Susanne},
	year = {2014},
}

@techreport{schlotzhauer_abstract_nodate,
	title = {Abstract - {Strength} grading of hardwood structural timber},
	author = {Schlotzhauer, Philipp},
}