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Fuhong Dai - One of the best experts on this subject based on the ideXlab platform.
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an analysis for snap through behavior of bi stable hybrid Symmetric Laminate with cantilever boundary
Composite Structures, 2021Co-Authors: Diankun Pan, Fuhong DaiAbstract:Abstract This paper focuses on a study of the snap-through behavior of a family of bi-stable plates constructed by hybrid Symmetric Laminates with a cantilever boundary. Involving shape change and actuation demand, a deep understanding of the snap-through behavior is of particular importance since this bi-stable Laminate is often served as a host structure of energy harvester or a morphing structure. The snap-through behavior is obtained using two displacement-controlled finite element procedures provided in the commercial software ABAQUS and the results are verified by experiments. The entire equilibrium path of reaction force-displacement response with a couple of zero load crossings is captured by the ‘Static, Riks’ procedure to reveal the potential nonlinear structural behavior. The practical situation of the reaction force-displacement curve is obtained by the ‘Static, General’ procedure which exhibits consistent results with experiments. Several characteristics, such as snap-down, hysteresis, negative stiffness, and even zero stiffness are captured. A parametric study including lay-up design and length is also carried out using the finite element model and verified by experiments. The results show that the lay-up design not only can fundamentally change the snap-through response but also influences other characteristics of this bi-stable Laminate including stable shape, and the length is a relatively reliable parameter to alter the snap-through features, e.g. peak force and hysteresis performance.
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dynamic analysis of bi stable hybrid Symmetric Laminate
Composite Structures, 2019Co-Authors: Diankun Pan, Weihong Jiang, Fuhong DaiAbstract:Abstract The resulting oscillation of bi-stable hybrid Symmetric Laminate could enable broadband energy harvesting via piezoelectric transduction. The aim of this work is to investigate its dynamic behaviors to provide the basis for designing broadband energy harvester. This paper proposes the dynamic analysis of this bi-stable Laminate, focusing on the intra-well dynamics around its stable states and the inter-well dynamics between two stable states. Two types of stacking sequence are performed for this bi-stable Laminate, and experimental testing with different harmonic excitations is carried out for each type of this bi-stable Laminate. The strain responses at three positions are monitored to investigate the dynamic responses. A finite element model is also developed to analyze the static strain distribution and capture the dynamics. The results show that the Laminates exhibit intra-well response under low-level excitation, and the inter-well response at a particular range frequency appears when excitation level increases. Different types of inter-well response mode involving the snap-through behavior are obtained in experiments, such as intermittent inter-well vibration and chaotic vibration. The presented results essentially highlight the need for considering the stacking sequence associated with the dynamics while designing the hybrid bi-stable Symmetric Laminate to obtain the desirable nonlinear response.
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piezoelectric energy harvester based on bi stable hybrid Symmetric Laminate
Composites Science and Technology, 2015Co-Authors: Diankun Pan, Fuhong DaiAbstract:Abstract A bi-stable piezoelectric energy harvester (BPEH) based on bi-stable hybrid Symmetric Laminate (BHSL) is proposed for energy harvesting. Due to its large deformation and low actuation, BPEH has better energy harvesting performance at low frequencies compared with traditional resonance cantilever-type energy harvester. Two types of stacking sequence and two types of piezoelectric ceramics (PZT) shapes with identical area were considered, and four types of BPEHs were designed. The stable configurations of the BPEHs and the stress states of PZT bonded on the surface of the BSHL were simulated and analyzed by finite element analysis. In addition, the four types of BPEHs were fabricated and experimentally evaluated. The BPEHs were actuated by hand shaking to transition between the two stable configurations. Using this method, the voltage outputs and power outputs were measured at two frequencies (2 Hz and 5 Hz). The results demonstrate that the BPEHs exhibited high output power because the PZTs on their surface were fully utilized due to their double curved shape and uniform deformations. The generated powers from the BPEHs were significantly higher than that observed from a similar sized cantilever-type piezoelectric harvester. Simultaneously, the influences of stacking sequence and shape of PZT on the energy harvesting performance were evaluated. The BPEHs with the second stacking sequence generated higher power than those of first stacking sequence, and the rectangular PZT performed better compared to the square. The measured maximum power output generated by the BPEH with the second stacking sequence and rectangular PZT was 37 mW at 5 Hz.
Diankun Pan - One of the best experts on this subject based on the ideXlab platform.
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an analysis for snap through behavior of bi stable hybrid Symmetric Laminate with cantilever boundary
Composite Structures, 2021Co-Authors: Diankun Pan, Fuhong DaiAbstract:Abstract This paper focuses on a study of the snap-through behavior of a family of bi-stable plates constructed by hybrid Symmetric Laminates with a cantilever boundary. Involving shape change and actuation demand, a deep understanding of the snap-through behavior is of particular importance since this bi-stable Laminate is often served as a host structure of energy harvester or a morphing structure. The snap-through behavior is obtained using two displacement-controlled finite element procedures provided in the commercial software ABAQUS and the results are verified by experiments. The entire equilibrium path of reaction force-displacement response with a couple of zero load crossings is captured by the ‘Static, Riks’ procedure to reveal the potential nonlinear structural behavior. The practical situation of the reaction force-displacement curve is obtained by the ‘Static, General’ procedure which exhibits consistent results with experiments. Several characteristics, such as snap-down, hysteresis, negative stiffness, and even zero stiffness are captured. A parametric study including lay-up design and length is also carried out using the finite element model and verified by experiments. The results show that the lay-up design not only can fundamentally change the snap-through response but also influences other characteristics of this bi-stable Laminate including stable shape, and the length is a relatively reliable parameter to alter the snap-through features, e.g. peak force and hysteresis performance.
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dynamic analysis of bi stable hybrid Symmetric Laminate
Composite Structures, 2019Co-Authors: Diankun Pan, Weihong Jiang, Fuhong DaiAbstract:Abstract The resulting oscillation of bi-stable hybrid Symmetric Laminate could enable broadband energy harvesting via piezoelectric transduction. The aim of this work is to investigate its dynamic behaviors to provide the basis for designing broadband energy harvester. This paper proposes the dynamic analysis of this bi-stable Laminate, focusing on the intra-well dynamics around its stable states and the inter-well dynamics between two stable states. Two types of stacking sequence are performed for this bi-stable Laminate, and experimental testing with different harmonic excitations is carried out for each type of this bi-stable Laminate. The strain responses at three positions are monitored to investigate the dynamic responses. A finite element model is also developed to analyze the static strain distribution and capture the dynamics. The results show that the Laminates exhibit intra-well response under low-level excitation, and the inter-well response at a particular range frequency appears when excitation level increases. Different types of inter-well response mode involving the snap-through behavior are obtained in experiments, such as intermittent inter-well vibration and chaotic vibration. The presented results essentially highlight the need for considering the stacking sequence associated with the dynamics while designing the hybrid bi-stable Symmetric Laminate to obtain the desirable nonlinear response.
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piezoelectric energy harvester based on bi stable hybrid Symmetric Laminate
Composites Science and Technology, 2015Co-Authors: Diankun Pan, Fuhong DaiAbstract:Abstract A bi-stable piezoelectric energy harvester (BPEH) based on bi-stable hybrid Symmetric Laminate (BHSL) is proposed for energy harvesting. Due to its large deformation and low actuation, BPEH has better energy harvesting performance at low frequencies compared with traditional resonance cantilever-type energy harvester. Two types of stacking sequence and two types of piezoelectric ceramics (PZT) shapes with identical area were considered, and four types of BPEHs were designed. The stable configurations of the BPEHs and the stress states of PZT bonded on the surface of the BSHL were simulated and analyzed by finite element analysis. In addition, the four types of BPEHs were fabricated and experimentally evaluated. The BPEHs were actuated by hand shaking to transition between the two stable configurations. Using this method, the voltage outputs and power outputs were measured at two frequencies (2 Hz and 5 Hz). The results demonstrate that the BPEHs exhibited high output power because the PZTs on their surface were fully utilized due to their double curved shape and uniform deformations. The generated powers from the BPEHs were significantly higher than that observed from a similar sized cantilever-type piezoelectric harvester. Simultaneously, the influences of stacking sequence and shape of PZT on the energy harvesting performance were evaluated. The BPEHs with the second stacking sequence generated higher power than those of first stacking sequence, and the rectangular PZT performed better compared to the square. The measured maximum power output generated by the BPEH with the second stacking sequence and rectangular PZT was 37 mW at 5 Hz.
Weihong Jiang - One of the best experts on this subject based on the ideXlab platform.
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dynamic analysis of bi stable hybrid Symmetric Laminate
Composite Structures, 2019Co-Authors: Diankun Pan, Weihong Jiang, Fuhong DaiAbstract:Abstract The resulting oscillation of bi-stable hybrid Symmetric Laminate could enable broadband energy harvesting via piezoelectric transduction. The aim of this work is to investigate its dynamic behaviors to provide the basis for designing broadband energy harvester. This paper proposes the dynamic analysis of this bi-stable Laminate, focusing on the intra-well dynamics around its stable states and the inter-well dynamics between two stable states. Two types of stacking sequence are performed for this bi-stable Laminate, and experimental testing with different harmonic excitations is carried out for each type of this bi-stable Laminate. The strain responses at three positions are monitored to investigate the dynamic responses. A finite element model is also developed to analyze the static strain distribution and capture the dynamics. The results show that the Laminates exhibit intra-well response under low-level excitation, and the inter-well response at a particular range frequency appears when excitation level increases. Different types of inter-well response mode involving the snap-through behavior are obtained in experiments, such as intermittent inter-well vibration and chaotic vibration. The presented results essentially highlight the need for considering the stacking sequence associated with the dynamics while designing the hybrid bi-stable Symmetric Laminate to obtain the desirable nonlinear response.
York, Mendeley C Data) - One of the best experts on this subject based on the ideXlab platform.
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Laminate Stiffness Tailoring for Improved Buckling Performance
2021Co-Authors: York, Mendeley C Data)Abstract:This data item provides supplementary information to a published article: York, C. B. (2021) Laminate stiffness tailoring for improved buckling performance. Thin-Walled Structures, 161, 107482. https://doi.org/10.1016/j.tws.2021.107482 Received 31 July 2020, Revised 18 November 2020, Accepted 20 January 2021, Available online 18 February 2021. The article presents a stiffness tailoring approach for improved buckling performance using double angle-ply Laminates. These special configurations are either stiffness matched to the extensional stiffness of equivalent balanced and Symmetric Laminate designs, or standard-ply designs, representing typical aircraft components, such as a spar, skin or stiffener, to identify configurations with improved buckling performance, or matched to specific bending stiffness properties, in order to achieve a buckling performance threshold. Tailored designs with matched isotropic properties in bending are used to demonstrate the influence of variation in axial stiffness on the stability of thin walled sections. Many of the designs can be tapered in thickness, through ply terminations, which permit tailoring of the bending stiffness properties between compression and shear dominant regions.The following electronic appendices are listed below:Appendix 1 - Balanced and Symmetric Standard-Ply DesignsAppendix 2 - Double Angle-Ply Designs Derived from Standard-Ply DesignsAppendix 3 - Double Angle-Ply DesignsAppendix 4 - Tapered Double Angle-Ply DesignsTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV
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Balanced and Symmetric Laminates with Bending-Twisting Coupling
2020Co-Authors: York, Mendeley C Data)Abstract:Balanced and Symmetric Quasi-Isotropic Laminates - Electronic annex to an article on Compression and Shear Buckling Performance of Finite Length Plates with Bending-Twisting Coupling: This electronic annex provides an extract from the Laminate database described below, for quasi-isotropic designs only, in which all designs share a single point, or coordinate (0,0), in the lamination parameter design space for extensional stiffness. Quasi-isotropic designs are often used for benchmarking purposes due to the simplification of the in-plane properties, but this simplification should never be assumed to extend to bending stiffness properties. For the Symmetric stacking sequences considered in the associated article, quasi-isotropic properties are found exclusively within 8 and 16 ply Laminates, for which there are 6 and 536 solutions, respectively. The stacking sequence listings for 16 ply Laminates are presented together with their lamination parameter coordinates. They are grouped by matching orthotropic bending stiffness to reveal the significant differences in Bending-Twisting coupling magnitude, where each grouping contains between 2 and 6 stacking sequences. Balanced and Symmetric Laminate Design Data - 10% Rule - Max Ply Contiguity 3 This spreadsheet contains the complete database of balanced and Symmetric designs, with Bending-Twisting coupling, to which the 10% rule has been applied, i.e., the minimum number of plies in each of the standard ply orientations. Ply contiguity constraints have also been applied, which limit the maximum number of adjacent plies with the same orientation to 3, as is now common design practice. For the meaning of the symbolic stacking sequence notation used, the reader is referred to the electronic annex described above
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Laminate Stiffness Tailoring for Improved Buckling Performance
2020Co-Authors: York, Mendeley C Data)Abstract:This data item provides supplementary information to an article entitled: Laminate Stiffness Tailoring for Improved Buckling Performance. The article presents a stiffness tailoring approach for improved buckling performance using double angle-ply Laminates. These special configurations are either stiffness matched to the extensional stiffness of equivalent balanced and Symmetric Laminate designs, or standard-ply designs, representing typical aircraft components, such as a spar, skin or stiffener, to identify configurations with improved buckling performance, or matched to specific bending stiffness properties, in order to achieve a buckling performance threshold. Tailored designs with matched isotropic properties in bending are used to demonstrate the influence of variation in axial stiffness on the stability of thin walled sections. Many of the designs can be tapered in thickness, through ply terminations, which permit tailoring of the bending stiffness properties between compression and shear dominant regions. The following electronic appendices are listed below: Appendix 1 - Balanced and Symmetric Standard-Ply Designs Appendix 2 - Double Angle-Ply Designs Derived from Standard-Ply Designs Appendix 3 - Double Angle-Ply Designs Appendix 4 - Tapered Double Angle-Ply Design
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Balanced and Symmetric Laminates with Bending-Twisting Coupling
2019Co-Authors: York, Mendeley C Data)Abstract:Balanced and Symmetric Quasi-Isotropic Laminates - Electronic annex to an article on Compression and Shear Buckling Performance of Finite Length Plates with Bending-Twisting Coupling: This electronic annex provides an extract from the Laminate database described below, for quasi-isotropic designs only, in which all designs share a single point, or coordinate (0,0), in the lamination parameter design space for extensional stiffness. Quasi-isotropic designs are often used for benchmarking purposes due to the simplification of the in-plane properties, but this simplification should never be assumed to extend to bending stiffness properties. For the Symmetric stacking sequences considered in the associated article, quasi-isotropic properties are found exclusively within 8 and 16 ply Laminates, for which there are 6 and 536 solutions, respectively. The stacking sequence listings for 16 ply Laminates are presented together with their lamination parameter coordinates. They are grouped by matching orthotropic bending stiffness to reveal the significant differences in Bending-Twisting coupling magnitude, where each grouping contains between 2 and 6 stacking sequences. Balanced and Symmetric Laminate Design Data - 10% Rule - Max Ply Contiguity 3 This spreadsheet contains the complete database of balanced and Symmetric designs, with Bending-Twisting coupling, to which the 10% rule has been applied, i.e., the minimum number of plies in each of the standard ply orientations. Ply contiguity constraints have also been applied, which limit the maximum of number of adjacent plies with the same orientation to 3, as is now common design practice. For the meaning of the symbolic stacking sequence notation used, the reader is reference to the electronic annex described above
L.n. Mccartney - One of the best experts on this subject based on the ideXlab platform.
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approximate method of predicting ply crack formation in general Symmetric Laminates subject to biaxial loading and bending
2008Co-Authors: L.n. MccartneyAbstract:Ply cracking is a very important damage mode for Laminated composite materials that has been the subject of intensive study over many years, especially cross-ply Laminates. In practical applications, Laminates are usually more complex than cross-plies, and they are subject to complex loading that involves both in-plane and out-of-plane deformation, in addition to residual stresses arising from thermal expansion mismatch effects between the plies. Based on a methodology that is able to predict ply cracking for: i) a multiple-ply cross-ply Laminate subject to combined biaxial in-plane loading and biaxial bending, and ii) a general Symmetric Laminate subject to combined in-plane biaxial loading and in-plane shear loading, where thermal residual stresses can be present, this paper will attempt to combine the models developed for these situations so that ply cracking in general Symmetric Laminates subject to combined in-plane biaxial and out-of-plane biaxial bending can be treated. It is first assumed that Laminates have at least one 90o ply, and that ply cracking occurs only in some of all of the 90o plies. The off-axis plies in the Laminate, which are uncracked, are first homogenised into an orthotropic effective medium. The next step is to apply the homogenised properties to the 0o plies of an equivalent hybrid cross-ply Laminate that is then subject to progressive loading involving any combination of in-plane biaxial loading and out-of-plane bending. The homogenisation approach is tested, for the case of uniaxial in-plane loading, by comparing predictions of the homogenised model with those of an existing model that allows for the presence of all the off-axis plies. For more complex loading states, an example will be given of a prediction of the progressive growth of ply cracking, and of Laminate stress-strain behaviour.
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effect of mixed mode loading on ply crack development in Laminated composites theory and application
2004Co-Authors: L.n. MccartneyAbstract:Mixed mode loading is always encountered near stress concentrations in composite components, such as holes in general Symmetric Laminates. The stress concentration effects lead to stress states that are a combination of biaxial and shear loading modes so that a mixed mode situation must be taken into account when considering the formation of ply cracking near the stress concentrations. This report is concerned with a proposed methodology for the development of a technique that can account for the effects of mixed mode loading on ply crack development in general Symmetric Laminates. The approach will indicate how the methodology, already developed to predict the effects of ply cracking on Laminate properties when ply crack growth occurs in mode I loading, can be extended to deal with ply crack growth in the mixed mode situations. These arise in practical applications, where combined mode I and mode II deformations are encountered at ply crack tips. The problem splits into two distinct stages. The first concerns the estimation of the availability of energy for ply crack development under mixed mode conditions that is addressed in this report. The second involves understanding the factors that control the resistance of the material in mixed mode situations (i.e. its effective fracture toughness). The criterion for first ply failure is based on a general form of energy balance that is designed to be flexible. It is clear from the preliminary results presented in this report that the choice of ply cracking criterion has a significant effect on the predictions for first ply failure. In particular it has been shown that the use of a total energy release rate criterion, in situations where ply crack growth is mixed mode, leads to predictions that are physically unreasonable, thus indicating the importance of deriving a physically realistic criterion for ply cracking. The analysis presented in this report is to be the basis of modifications to a software system that has recently been developed using homogenisation techniques to take account of ply crack formation in more than one orientation in any general Symmetric Laminate. The inclusion of mixed mode effects are expected to lead to more accurate simulations of both damage development and strength predictions. The software will also be used to upgrade the PREDICT module of the NPL Composites Design Analysis (CoDA) software system.
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Generalised framework for the prediction of ply cracking in any Symmetric Laminate subject to general in-plane loading.
1996Co-Authors: L.n. MccartneyAbstract:This report describes a general theoretical framework that leads to a new method of predicting ply crack formation in the 900 plies of general Symmetric Laminates subject to general in-plane loading involving combined biaxial and shear loading. The methodology takes full account of thermal residual stresses and assumes that there is at least one 90o ply in the Laminate. The analysis assumes that the plies deform as linear thermo-elastic solids, that damage is effectively homogeneous at the macroscopic level, and that the ply cracks are not subject to compressive or shear loading. Within the assumptions made the results presented are independent of any detailed stress analysis associated with stress transfer models for ply cracks in Laminates, and are thus exact. The methodology results in relatively simple relationships that are defined at the macroscopic Laminate level even though the ply cracking occurs at the microstructural ply level. Stress transfer models predicting the stress and displacement distributions in Laminates having a distribution of fully developed ply cracks are needed only to predict the macroscopic effective thermo-elastic constants of cracked Laminates. The theoretical framework governing ply crack formation in general Symmetric Laminates subject to conditions of general in-plane loading, when combined with the accuracy and relative simplicity of results, has good potential for becoming the basis of future design methodology. The approach described can in principle be extended to deal with any form of damage provided that cracks and delaminations are open, and to include moisture effects, assuming that the moisture distribution is uniform within each ply.
