In the present study, artificial neural network（ANN） approach was used to predict the stress-strain curve of near beta titanium alloy as a function of volume fractions of a and b. This approach is to develop the bes...In the present study, artificial neural network（ANN） approach was used to predict the stress-strain curve of near beta titanium alloy as a function of volume fractions of a and b. This approach is to develop the best possible combination or neural network（NN） to predict the stress-strain curve. In order to achieve this, three different NN architectures（feed-forward back-propagation network,cascade-forward back-propagation network, and layer recurrent network）, three different transfer functions（purelin, Log-Sigmoid, and Tan-Sigmoid）, number of hidden layers（1 and 2）, number of neurons in the hidden layer（s）,and different training algorithms were employed. ANN training modules, the load in terms of strain, and volume fraction of a are the inputs and the stress as an output.ANN system was trained using the prepared training set（a,16 % a, 40 % a, and b stress-strain curves）. After training process, test data were used to check system accuracy. It is observed that feed-forward back-propagation network is the fastest, and Log-Sigmoid transfer function is giving the best results. Finally, layer recurrent NN with a single hidden layer consists of 11 neurons, and Log-Sigmoid transfer function using trainlm as training algorithm is giving good result, and average relative error is1.27 ± 1.45 %. In two hidden layers, layer recurrent NN consists of 7 neurons in each hidden layer with trainrp as the training algorithm having the transfer function of LogSigmoid which gives better results. As a result, the NN is founded successful for the prediction of stress-strain curve of near b titanium alloy.展开更多
Fibre bundle tensile curves can be used to characterise fibre processing properties and end-use performance directly and to predict single-fibre properties in theory. In this paper, the tensile behaviour of polyester ...Fibre bundle tensile curves can be used to characterise fibre processing properties and end-use performance directly and to predict single-fibre properties in theory. In this paper, the tensile behaviour of polyester fibre-bundles has been analysed in characteristic values and diagramming. The characteristic distributions which include the symmetry distribution on right part, SRBS′ (e), on left part, SLBS′(e) and the curve on base-line modification, MBS′ (e),based on the modulus distribution, BS′ (e), as well as the frequency density function of broken fibres, B′ (e), have been derived from the tail of bundle tensile curves. The theoretical and measured results show that the most important curves are MBS′ ( e ) and B′ ( e ) and can be used to estimate the breaking-extension distribution of single fibres. Especially for MBS′(e), the modulus distribution can accurately characterize single-fibre tensile properties and is no limitation as the calculation of B′(e) because the bundle specific stress Y(e) of no fibre breaking at extension e should be found at first.展开更多
文摘In the present study, artificial neural network（ANN） approach was used to predict the stress-strain curve of near beta titanium alloy as a function of volume fractions of a and b. This approach is to develop the best possible combination or neural network（NN） to predict the stress-strain curve. In order to achieve this, three different NN architectures（feed-forward back-propagation network,cascade-forward back-propagation network, and layer recurrent network）, three different transfer functions（purelin, Log-Sigmoid, and Tan-Sigmoid）, number of hidden layers（1 and 2）, number of neurons in the hidden layer（s）,and different training algorithms were employed. ANN training modules, the load in terms of strain, and volume fraction of a are the inputs and the stress as an output.ANN system was trained using the prepared training set（a,16 % a, 40 % a, and b stress-strain curves）. After training process, test data were used to check system accuracy. It is observed that feed-forward back-propagation network is the fastest, and Log-Sigmoid transfer function is giving the best results. Finally, layer recurrent NN with a single hidden layer consists of 11 neurons, and Log-Sigmoid transfer function using trainlm as training algorithm is giving good result, and average relative error is1.27 ± 1.45 %. In two hidden layers, layer recurrent NN consists of 7 neurons in each hidden layer with trainrp as the training algorithm having the transfer function of LogSigmoid which gives better results. As a result, the NN is founded successful for the prediction of stress-strain curve of near b titanium alloy.
文摘Fibre bundle tensile curves can be used to characterise fibre processing properties and end-use performance directly and to predict single-fibre properties in theory. In this paper, the tensile behaviour of polyester fibre-bundles has been analysed in characteristic values and diagramming. The characteristic distributions which include the symmetry distribution on right part, SRBS′ (e), on left part, SLBS′(e) and the curve on base-line modification, MBS′ (e),based on the modulus distribution, BS′ (e), as well as the frequency density function of broken fibres, B′ (e), have been derived from the tail of bundle tensile curves. The theoretical and measured results show that the most important curves are MBS′ ( e ) and B′ ( e ) and can be used to estimate the breaking-extension distribution of single fibres. Especially for MBS′(e), the modulus distribution can accurately characterize single-fibre tensile properties and is no limitation as the calculation of B′(e) because the bundle specific stress Y(e) of no fibre breaking at extension e should be found at first.
