•The interface friction in aramid fabrics for different weaving types is considered.•The required range for the compressive loads is estimated by FE-modelling.•The type of weaving influences the ...interface friction coefficients.•The experimental device is proposed for pulling out a fabric under the compression.•The numerical modelling of the load distribution in the specimen is accomplished.
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Experimental investigation and computational estimation of the interface friction in aramid woven fabrics for different weaving types are performed under the conditions of the transverse compression. The required range for the compressive loads is estimated by the use of FE-modelling of impact loading of the multi-layer woven barriers. For the moderate values of transverse compression the simple sliding test for two fabric layers under the conditions of the transverse pressure was carried out. The parameters of friction are determined for the cases of textile-textile interfaces for different weaving types. It is obtained that the combination of fabrics of different weaving types can have the mutual static friction coefficient differing from the coefficients for each component up to 20%. Moreover, it can also differ from the averaged value of these two coefficients. For the higher values of the transverse compression the experimental equipment is proposed and designed for pulling out a textile layer from a free multilayer structure of fabrics under the conditions of controllable transverse compression loading. The numerical modelling of the load distribution in the tested fabric layer is accomplished which allows us to estimate the irregularity of the transverse pressure in the specimen and to correct the experimental results for friction coefficients. The transverse elastic modules used in these simulations were obtained separately by means of compression tests for the multilayer fabric samples. All the friction tests were carried out using Zwick/Roell 100 experimental device and the results are presented for various pulling rates and transverse loads. It is obtained that the pulling rate has a weak influence on the interface textile friction in the range of rates under consideration.
We propose a new method based on machine learning to
play the devil’s advocate
and investigate the impact of unknown systematic effects in a quantitative way. This method proceeds by reversing the ...measurement process and using the physics results to interpret systematic effects under the Standard Model hypothesis. We explore this idea with two alternative approaches: the first one relies on a combination of gradient descent and optimisation techniques, its application and potentiality is illustrated with an example that studies the branching fraction measurement of a heavy-flavour decay. The second method employs reinforcement learning and it is applied to the determination of the
P
5
′
angular observable in
B
0
→
K
∗
0
μ
+
μ
-
decays. We find that for the former, the size of a hypothetical hidden systematic uncertainty strongly depends on the kinematic overlap between the signal and normalisation channel, while the latter is very robust against possible mismodellings of the efficiency.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We propose a new method based on machine learning to \emph{play the devil's advocate} and investigate the impact of unknown systematic effects in a quantitative way. This method proceeds by reversing ...the measurement process and using the physics results to interpret systematic effects under the Standard Model hypothesis. We explore this idea with two alternative approaches: the first one relies on a combination of gradient descent and optimisation techniques, its application and potentiality is illustrated with an example that studies the branching fraction measurement of a heavy-flavour decay. The second method employs reinforcement learning and it is applied to the determination of the \(P_{5}^{'}\) angular observable in \(B^0 \to K^{*0} \mu^+\mu^-\) decays. We find that for the former, the size of a hypothetical hidden systematic uncertainty strongly depends on the kinematic overlap between the signal and normalisation channel, while the latter is very robust against possible mismodellings of the efficiency.
