2014
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Baumer, A.; Kastenmeier, A.; Ehrlich, I. Investigation of Bolted Composite Joints with Different Reinforcement Elements at the Bolt Hole. Leichtbau Proceedings Article In: Ziemann, O.; Mottok, J.; Pforr, J. (Ed.): Applied Research Conference 2014 – ARC 2014, pp. 255–258, Shaker-Verlag, 2014, ISBN: 978-3844028751. @inproceedings{Baumer2014,
title = {Investigation of Bolted Composite Joints with Different Reinforcement Elements at the Bolt Hole.},
author = {A. Baumer and A. Kastenmeier and I. Ehrlich},
editor = {O. Ziemann and J. Mottok and J. Pforr},
isbn = {978-3844028751},
year = {2014},
date = {2014-07-15},
booktitle = {Applied Research Conference 2014 – ARC 2014},
pages = {255--258},
publisher = {Shaker-Verlag},
abstract = {Nowadays, there are hardly any structures without joints. On this occasion connections of composite materials with metallic components depict a particular challenge in the structural design. Bolted joints pose a significant weak point in the composite structure because of the strength step from composite to metal and the notch effect of the bolt hole. Nevertheless, such joints are often used in the vehicle and special vehicle construction, as these form-fitting joints can be implemented relatively simple and inexpensively. However, for highly stressed composite structures bolted joints show an insufficient strength. To improve the mechanical properties of the joint, there are various methods for reinforcing the bolt hole in the fiber reinforced plastic. The aim of this research project is to simulate different reinforced bolted joints on CRP (Carbon fiber Reinforced Plastic) pipe structures with the finite-element-method, manufacturing prototypes with the filament winding technique and then to examine experimentally in view of the mechanical properties, e.g. bearing and tensile strength. Before the tests are carried out on pipe structures, first of all the process of manufacturing and testing of reinforced bolted joints is developed for plane samples. These plane bolted joint samples of steel and CRP are tested for tension and bearing strength.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Nowadays, there are hardly any structures without joints. On this occasion connections of composite materials with metallic components depict a particular challenge in the structural design. Bolted joints pose a significant weak point in the composite structure because of the strength step from composite to metal and the notch effect of the bolt hole. Nevertheless, such joints are often used in the vehicle and special vehicle construction, as these form-fitting joints can be implemented relatively simple and inexpensively. However, for highly stressed composite structures bolted joints show an insufficient strength. To improve the mechanical properties of the joint, there are various methods for reinforcing the bolt hole in the fiber reinforced plastic. The aim of this research project is to simulate different reinforced bolted joints on CRP (Carbon fiber Reinforced Plastic) pipe structures with the finite-element-method, manufacturing prototypes with the filament winding technique and then to examine experimentally in view of the mechanical properties, e.g. bearing and tensile strength. Before the tests are carried out on pipe structures, first of all the process of manufacturing and testing of reinforced bolted joints is developed for plane samples. These plane bolted joint samples of steel and CRP are tested for tension and bearing strength. |
Romano, M.; Hoinkes, C.; Ehrlich, I.; Höcherl, J.; Gebbeken, N. Experimental investigation of fibre reinforced plastics with hybrid layups under high-velocity impact loads. Leichtbau Journal Article In: Frattura ed Integrità Strutturale (Fracture and Structural Integrity), vol. 8, no. 29, pp. 385-398, 2014, ISSN: 1971-8993. @article{Romano2014,
title = {Experimental investigation of fibre reinforced plastics with hybrid layups under high-velocity impact loads. },
author = {M. Romano and C. Hoinkes and I. Ehrlich and J. Höcherl and N. Gebbeken},
url = {http://www.fracturae.com/index.php/fis/article/view/IGF-ESIS.29.34
http://www.fracturae.com/index.php/fis/article/view/IGF-ESIS.29.34/1219
http://www.fracturae.com/index.php/fis/article/download/IGF-ESIS.29.34/1219
},
doi = {10.3221/IGF-ESIS.29.34 },
issn = {1971-8993},
year = {2014},
date = {2014-07-09},
journal = {Frattura ed Integrità Strutturale (Fracture and Structural Integrity)},
volume = {8},
number = {29},
pages = {385-398},
abstract = {This paper deals with experimental investigations concerning energy dissipation capacity of different kinds of reinforcement fibres in monolithic and hybrid layups under high-velocity impact loads. The investigated kinds of fibres are carbon, glass and basalt fibres. Therefore test panels, using the same thermoset resin, were built up and cured by autoclave processing. The fibre volume content of the test panels has been determined. Furthermore the influence of a separating layer at selected positions in the hybrid stacked panels was investigated. The results show the influence and the energy dissipation capacity of each single kind of fibre and the enhanced properties for the hybrid layups by hybrid stacking sequences and the use of a separating core material.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This paper deals with experimental investigations concerning energy dissipation capacity of different kinds of reinforcement fibres in monolithic and hybrid layups under high-velocity impact loads. The investigated kinds of fibres are carbon, glass and basalt fibres. Therefore test panels, using the same thermoset resin, were built up and cured by autoclave processing. The fibre volume content of the test panels has been determined. Furthermore the influence of a separating layer at selected positions in the hybrid stacked panels was investigated. The results show the influence and the energy dissipation capacity of each single kind of fibre and the enhanced properties for the hybrid layups by hybrid stacking sequences and the use of a separating core material. |
Gomez, D. Ibanez; Kastenmeier, A.; Ehrlich, I. Development and construction of a winding machine for the production of composite tubes. Leichtbau Proceedings Article In: Ziemann, O.; Mottok, J.; Pforr, J. (Ed.): Applied Research Conference 2014 – ARC 2014, pp. 315–318, Ostbayerische Technische Hochschule Regensburg Shaker-Verlag, 2014, ISBN: 978-3844028751. @inproceedings{IbanezGomez2014,
title = {Development and construction of a winding machine for the production of composite tubes.},
author = {D. Ibanez Gomez and A. Kastenmeier and I. Ehrlich},
editor = {O. Ziemann and J. Mottok and J. Pforr},
isbn = {978-3844028751},
year = {2014},
date = {2014-06-01},
booktitle = {Applied Research Conference 2014 – ARC 2014},
pages = {315--318},
publisher = {Shaker-Verlag},
organization = {Ostbayerische Technische Hochschule Regensburg},
abstract = {The project is about the development and construction of a filament winding machine. The aim of the project is that the laboratory of composite technology of the Ostbayerische Technische Hochschule Regensburg is able to produce composite tube specimens in laboratory scale, so that different tube geometries can be manufactured. With a own machine the lab is able to produce many different specimens. Furthermore, the lab is able to test in additional machines different force transmissions or respectively connections of the tubes with metal flanges. Presently there is no possibility for the lab to produce tube specimens. In fact the winding technology already exists on the market, but for the lab it is important to have a machine with the right properties. For example the functions of the machine must be adjusted to the specifications of the tube specimens. The machine is constructed of four modules: a pre-load-, an impregnation-, a slide- and a mandrel-module. The function of the pre-load module is to aplly a defined load to the rovings. In the impregnation module the rovings are wetted with resin. The combination of the slide- and mandrel-module enables the define depositting of the rovings on the mandrel. The VDI guideline 2221 is used to develop the winding machine. In this guideline the approach of the development is defined. The first step is to define the requirements. After that a theoretical solution has to be found and this solution has to be elaborated. Finally, the concept has to be optimized for the assembly.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
The project is about the development and construction of a filament winding machine. The aim of the project is that the laboratory of composite technology of the Ostbayerische Technische Hochschule Regensburg is able to produce composite tube specimens in laboratory scale, so that different tube geometries can be manufactured. With a own machine the lab is able to produce many different specimens. Furthermore, the lab is able to test in additional machines different force transmissions or respectively connections of the tubes with metal flanges. Presently there is no possibility for the lab to produce tube specimens. In fact the winding technology already exists on the market, but for the lab it is important to have a machine with the right properties. For example the functions of the machine must be adjusted to the specifications of the tube specimens. The machine is constructed of four modules: a pre-load-, an impregnation-, a slide- and a mandrel-module. The function of the pre-load module is to aplly a defined load to the rovings. In the impregnation module the rovings are wetted with resin. The combination of the slide- and mandrel-module enables the define depositting of the rovings on the mandrel. The VDI guideline 2221 is used to develop the winding machine. In this guideline the approach of the development is defined. The first step is to define the requirements. After that a theoretical solution has to be found and this solution has to be elaborated. Finally, the concept has to be optimized for the assembly. |
Micklitz, M.; Romano, M.; Ehrlich, I.; Gebbeken, N. The influence of ondulations in fabric reinforced layers on the damping properties of fibre-reinforced plastics Leichtbau Proceedings Article In: Ziemann, O.; Mottok, J.; Pforr, J. (Ed.): Applied Research Conference 2014 – ARC 2014, pp. 306–310, Ostbayerische Technische Hochschule Regensburg Shaker-Verlag, 2014, ISBN: 978-3844028751. @inproceedings{Micklitz2014,
title = {The influence of ondulations in fabric reinforced layers on the damping properties of fibre-reinforced plastics},
author = {M. Micklitz and M. Romano and I. Ehrlich and N. Gebbeken},
editor = {O. Ziemann and J. Mottok and J. Pforr},
isbn = {978-3844028751},
year = {2014},
date = {2014-06-01},
booktitle = {Applied Research Conference 2014 – ARC 2014},
pages = {306--310},
publisher = {Shaker-Verlag},
organization = {Ostbayerische Technische Hochschule Regensburg},
abstract = {Ondulations in fabric-reinforced single layers are caused by alternatingly crossing of warp and fill yarns. In order to determine the influence of the ondulations in fabrics on the damping properties of fibre-reinforced plastics, the structural dynamic properties of fabric-reinforced and unidirectionally reinforced Plastics are investigated. Therefore, vibration experiments are carried outby the free-decay method. Fabric-reinforced and unidriectionally reinforced flat beamlike specimens were cut out of test panels by waterjet cutting. The test panels were impregnated via pre-impregnation in case of the fabric-reinforced material, and filament winding in case of the unidirectionally reinforced material. In both cases the same thermoset resin has been used, in order to ensure maximum comparability between the different specimens. In order to additionally obtain comparable fibre volume contents of approx. 60 %, curing was done by autoclave processing. In detail the structural mechanical investigations are carried out by the free decay of fixed-free specimens after reproducible displacement excitations. The vibrating structure has been measured by a laser scanning vibrometer PSV 400 from Polytec. The evaluation of the results for the specimen with unidirectional and fabric reinforcement yields enhanced damping properties.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Ondulations in fabric-reinforced single layers are caused by alternatingly crossing of warp and fill yarns. In order to determine the influence of the ondulations in fabrics on the damping properties of fibre-reinforced plastics, the structural dynamic properties of fabric-reinforced and unidirectionally reinforced Plastics are investigated. Therefore, vibration experiments are carried outby the free-decay method. Fabric-reinforced and unidriectionally reinforced flat beamlike specimens were cut out of test panels by waterjet cutting. The test panels were impregnated via pre-impregnation in case of the fabric-reinforced material, and filament winding in case of the unidirectionally reinforced material. In both cases the same thermoset resin has been used, in order to ensure maximum comparability between the different specimens. In order to additionally obtain comparable fibre volume contents of approx. 60 %, curing was done by autoclave processing. In detail the structural mechanical investigations are carried out by the free decay of fixed-free specimens after reproducible displacement excitations. The vibrating structure has been measured by a laser scanning vibrometer PSV 400 from Polytec. The evaluation of the results for the specimen with unidirectional and fabric reinforcement yields enhanced damping properties. |
Niedernhuber, M.; Ehrlich, I.; Holtmannspötter, J. Fiber-Oriented Repair of Fiber Reinforced Plastics: Investigations on Tensile Specimens Leichtbau Proceedings Article In: Ziemann, O.; Mottok, J.; Pforr, J. (Ed.): Applied Research Conference 2014 – ARC 2014, pp. 298–302, Ostbayerische Technische Hochschule Regensburg Shaker-Verlag, 2014, ISBN: 978-3844028751. @inproceedings{Niedernhuber2014,
title = {Fiber-Oriented Repair of Fiber Reinforced Plastics: Investigations on Tensile Specimens},
author = {M. Niedernhuber and I. Ehrlich and J. Holtmannspötter},
editor = {O. Ziemann and J. Mottok and J. Pforr},
isbn = {978-3844028751},
year = {2014},
date = {2014-06-01},
booktitle = {Applied Research Conference 2014 – ARC 2014},
pages = {298--302},
publisher = {Shaker-Verlag},
organization = {Ostbayerische Technische Hochschule Regensburg},
abstract = {To minimize the repair area for fiber reinforced plastics (FRP), a new scarfing method is under investigation. For unidirectional plies, the idea is to perform a stepped scarf in fiber direction only. In theory, the repair area can be reduced up to 50 percent. Repair geometries generated with this method display varying overlap lengths in specific directions. With tensile tests of specimens according to german standards, a first comparison of mechanical values and joint strength between fiber-oriented scarfs and traditionally stepped scarfs in carbon fiber reinforced plastics (CFRP) was carried out. Mechanical values of the joint specimens showed only minor differences to intact laminates. The tensile strength of the stepped scarf and fiber-oriented scarf joints were around 50 % relative to the intact laminate. Our results show that the shorter overlap lengths in the plies of the fiber-oriented joints did not lead to the failure of specimen, instead, the butt joint on the outer surfaces of the specimens seem to be the initial point of failure.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
To minimize the repair area for fiber reinforced plastics (FRP), a new scarfing method is under investigation. For unidirectional plies, the idea is to perform a stepped scarf in fiber direction only. In theory, the repair area can be reduced up to 50 percent. Repair geometries generated with this method display varying overlap lengths in specific directions. With tensile tests of specimens according to german standards, a first comparison of mechanical values and joint strength between fiber-oriented scarfs and traditionally stepped scarfs in carbon fiber reinforced plastics (CFRP) was carried out. Mechanical values of the joint specimens showed only minor differences to intact laminates. The tensile strength of the stepped scarf and fiber-oriented scarf joints were around 50 % relative to the intact laminate. Our results show that the shorter overlap lengths in the plies of the fiber-oriented joints did not lead to the failure of specimen, instead, the butt joint on the outer surfaces of the specimens seem to be the initial point of failure. |
