The Experts below are selected from a list of 18 Experts worldwide ranked by ideXlab platform
Christoph Frommel - One of the best experts on this subject based on the ideXlab platform.
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EVALUATING THE Draping Quality OF MECHANICAL PREFORMED CARBON FIBRE TEXTILES FOR DOUBLE CURVED GEOMETRIES
2018Co-Authors: Christoph Frommel, Marian Korber, Marcin Malecha, Monika Mayer, Alfons Schuster, Mark WillmerothAbstract:Manufacturing of large carbon fibre reinforced plastic (CFRP) structures needs to be automated to fulfil the rising amount of aircrafts ordered worldwide. The main aspect of using CFRP structures is the low weight associated with high mechanical properties. To achieve these properties the fibre orientation is mandatory. Nevertheless, the complex part of preforming large structures is commonly done by hand due to the difficulty in handling the fragile fabrics. The approach at the DLR to automate this process is the usage of robotically controlled kinematic endeffectors. To make this process attractive for manufacturers the Quality of the draped cut pieces needs to meet the requirements specified by the design engineers. In this paper a dry carbon fibre cut piece was draped by a kinematic endeffector. The Draping simulation parameters were adjusted from the manual manufacturing to the Draping process by the endeffector. The draped cut pieces were then measured regarding the placement position via laser scanner and resulting fibre angles by an optical measurement system. Concluding the measured values where compared to the results of the simulation.
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SENSOR-SUPPORTED GRIPPER SURFACES FOR OPTICAL MONITORING OF Draping PROCESSES
2017Co-Authors: Marian Korber, Christoph FrommelAbstract:With the aid of the optical sensor system, the user is able to monitor the Draping process online or to evaluate it using stored data. Using these data, it was demonstrated that the Draping behavior of consolidated and non-consolidated fabrics differed from each other. The consolidated fabric reacts similarly to a non-drapable material because the stresses are horizon-tally and vertically degraded rather than along the fiber direction, as occurs with the non-consolidated fabric. Due to the gliding direction along the fibers, the latter material behaves as pre-dicted in theory. This provides us with the predictability of the Draping behavior. Also, the data suggest the higher drapability, which is unambiguous given because of the low shear strength. On the basis of this fact, the non-consolidated fabric should be used in subsequent test runs. The data additionally show that the Draping processes differ from one test run to another despite the identical process configuration. The non-consolidated fabric has on average the lowest gliding be-havior, but the larger variation over all six test runs. This suggests that during the Draping process, particularly the easily drapable materials have different effects which cannot be foreseen. In the following studies, the sensor data should be used to optimize the Draping Quality in the sense of deviation from the real to theoretically determined fiber angles and wrinkle formation of the cut-piece positioned in the tooling. For this purpose, a large number of test runs have to be carried out in which the suction intensity of the suction units will be varied and this configuration will be eval-uated by means of the fiber angle and boundary curve sensor data. The goal will be to develop an optimal Draping strategy, which can be documented on the one hand with the help of the sensory data and on the other hand it can help to counteract Draping deviations of the actual to the optimal gliding behavior. For this, it will be necessary to intervene online in the Draping process. For such an active Draping mechanism, a control system must be developed which is capable of influencing the holding forces of the suction units by varying the volumetric flow. If the system now detects an actual sliding vector deviating from the target, the system can intervene. It can reinforce the holding force in the area correspondingly if a deviating gliding behavior has taken place or reduce the holding force if it prevents a required gliding.
Mark Willmeroth - One of the best experts on this subject based on the ideXlab platform.
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EVALUATING THE Draping Quality OF MECHANICAL PREFORMED CARBON FIBRE TEXTILES FOR DOUBLE CURVED GEOMETRIES
2018Co-Authors: Christoph Frommel, Marian Korber, Marcin Malecha, Monika Mayer, Alfons Schuster, Mark WillmerothAbstract:Manufacturing of large carbon fibre reinforced plastic (CFRP) structures needs to be automated to fulfil the rising amount of aircrafts ordered worldwide. The main aspect of using CFRP structures is the low weight associated with high mechanical properties. To achieve these properties the fibre orientation is mandatory. Nevertheless, the complex part of preforming large structures is commonly done by hand due to the difficulty in handling the fragile fabrics. The approach at the DLR to automate this process is the usage of robotically controlled kinematic endeffectors. To make this process attractive for manufacturers the Quality of the draped cut pieces needs to meet the requirements specified by the design engineers. In this paper a dry carbon fibre cut piece was draped by a kinematic endeffector. The Draping simulation parameters were adjusted from the manual manufacturing to the Draping process by the endeffector. The draped cut pieces were then measured regarding the placement position via laser scanner and resulting fibre angles by an optical measurement system. Concluding the measured values where compared to the results of the simulation.
Marian Korber - One of the best experts on this subject based on the ideXlab platform.
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EVALUATING THE Draping Quality OF MECHANICAL PREFORMED CARBON FIBRE TEXTILES FOR DOUBLE CURVED GEOMETRIES
2018Co-Authors: Christoph Frommel, Marian Korber, Marcin Malecha, Monika Mayer, Alfons Schuster, Mark WillmerothAbstract:Manufacturing of large carbon fibre reinforced plastic (CFRP) structures needs to be automated to fulfil the rising amount of aircrafts ordered worldwide. The main aspect of using CFRP structures is the low weight associated with high mechanical properties. To achieve these properties the fibre orientation is mandatory. Nevertheless, the complex part of preforming large structures is commonly done by hand due to the difficulty in handling the fragile fabrics. The approach at the DLR to automate this process is the usage of robotically controlled kinematic endeffectors. To make this process attractive for manufacturers the Quality of the draped cut pieces needs to meet the requirements specified by the design engineers. In this paper a dry carbon fibre cut piece was draped by a kinematic endeffector. The Draping simulation parameters were adjusted from the manual manufacturing to the Draping process by the endeffector. The draped cut pieces were then measured regarding the placement position via laser scanner and resulting fibre angles by an optical measurement system. Concluding the measured values where compared to the results of the simulation.
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SENSOR-SUPPORTED GRIPPER SURFACES FOR OPTICAL MONITORING OF Draping PROCESSES
2017Co-Authors: Marian Korber, Christoph FrommelAbstract:With the aid of the optical sensor system, the user is able to monitor the Draping process online or to evaluate it using stored data. Using these data, it was demonstrated that the Draping behavior of consolidated and non-consolidated fabrics differed from each other. The consolidated fabric reacts similarly to a non-drapable material because the stresses are horizon-tally and vertically degraded rather than along the fiber direction, as occurs with the non-consolidated fabric. Due to the gliding direction along the fibers, the latter material behaves as pre-dicted in theory. This provides us with the predictability of the Draping behavior. Also, the data suggest the higher drapability, which is unambiguous given because of the low shear strength. On the basis of this fact, the non-consolidated fabric should be used in subsequent test runs. The data additionally show that the Draping processes differ from one test run to another despite the identical process configuration. The non-consolidated fabric has on average the lowest gliding be-havior, but the larger variation over all six test runs. This suggests that during the Draping process, particularly the easily drapable materials have different effects which cannot be foreseen. In the following studies, the sensor data should be used to optimize the Draping Quality in the sense of deviation from the real to theoretically determined fiber angles and wrinkle formation of the cut-piece positioned in the tooling. For this purpose, a large number of test runs have to be carried out in which the suction intensity of the suction units will be varied and this configuration will be eval-uated by means of the fiber angle and boundary curve sensor data. The goal will be to develop an optimal Draping strategy, which can be documented on the one hand with the help of the sensory data and on the other hand it can help to counteract Draping deviations of the actual to the optimal gliding behavior. For this, it will be necessary to intervene online in the Draping process. For such an active Draping mechanism, a control system must be developed which is capable of influencing the holding forces of the suction units by varying the volumetric flow. If the system now detects an actual sliding vector deviating from the target, the system can intervene. It can reinforce the holding force in the area correspondingly if a deviating gliding behavior has taken place or reduce the holding force if it prevents a required gliding.
Razidah Ismail - One of the best experts on this subject based on the ideXlab platform.
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Durable Press Reference for cotton and polyester/cotton fabrics
2010 International Conference on Science and Social Research (CSSR 2010), 2010Co-Authors: Salmiah Mohd. Nor, Wan Yunus Wan Ahmad, Jamil Salleh, Nora Zakaria, Razidah IsmailAbstract:A Durable Press (DP) finish of NuDURA PRESS® was applied on light and medium weight cotton and polyester/cotton (65/35) fabrics after dyeing and in a single bath process of combined dyeing and finishing. The DP formulation consisted of low formaldehyde durable press agent with polysiloxane softener, applied by the pad-dry-cure method in a manufacturing process at the textile mill. The finished fabrics have improved properties of wrinkle resistance and Draping Quality. The wrinkle resistance was determined by the wrinkle recovery angle (WRA) and appearance, while that of the Draping Quality by the stiffness and drape coefficient. A Durable Press Reference (DPR) was formulated using values of wrinkle resistance and Draping Quality. The DPR for finished fabrics after dyeing was 3.46 to 7.15, while that in a single bath process of combined dyeing and finishing was 3.39 to 6.04, differently for each fabric. The DPR formula can be used to evaluate objectively the DP performances of fabrics.
Salmiah Mohd. Nor - One of the best experts on this subject based on the ideXlab platform.
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Durable Press Reference for cotton and polyester/cotton fabrics
2010 International Conference on Science and Social Research (CSSR 2010), 2010Co-Authors: Salmiah Mohd. Nor, Wan Yunus Wan Ahmad, Jamil Salleh, Nora Zakaria, Razidah IsmailAbstract:A Durable Press (DP) finish of NuDURA PRESS® was applied on light and medium weight cotton and polyester/cotton (65/35) fabrics after dyeing and in a single bath process of combined dyeing and finishing. The DP formulation consisted of low formaldehyde durable press agent with polysiloxane softener, applied by the pad-dry-cure method in a manufacturing process at the textile mill. The finished fabrics have improved properties of wrinkle resistance and Draping Quality. The wrinkle resistance was determined by the wrinkle recovery angle (WRA) and appearance, while that of the Draping Quality by the stiffness and drape coefficient. A Durable Press Reference (DPR) was formulated using values of wrinkle resistance and Draping Quality. The DPR for finished fabrics after dyeing was 3.46 to 7.15, while that in a single bath process of combined dyeing and finishing was 3.39 to 6.04, differently for each fabric. The DPR formula can be used to evaluate objectively the DP performances of fabrics.
