Pub Date : 2022-07-16DOI: 10.1177/10996362221115420
Arash Farshidi, C. Berggreen
Disbond damage growth in honeycomb cored sandwich structures due to static and fatigue mixed mode loading is investigated numerically and experimentally. A two dimensional finite element model was generated using core homogenization and the Crack Surface Displacement Extrapolation mode separation method, integrated into a fracture mechanics based analysis sub-routine to predict face/core interface fatigue crack propagation. The Cycle Jump technique was furthermore applied to accelerate fatigue analysis. Mixed mode fatigue characterization testing was conducted using Double Cantilever Beam specimens loaded with Uneven Bending Moments, generating a relationship between crack propagation rates and energy release rate amplitudes as a modified Paris Law, measured at three mode-mixity phase angles. The measured Paris laws were subsequently used as input data for the numerical fatigue model. The numerical model was validated against CFRP/Nomex® Sandwich Tearing Test specimen tests with a propagating face/core interface crack yielding varying mode-mixities. The results from the validation showed good agreement between numerical predictions and experimental measurements.
{"title":"Face/core disbond fatigue growth in honeycomb cored aircraft sandwich elements under mixed mode flatwise tension loading","authors":"Arash Farshidi, C. Berggreen","doi":"10.1177/10996362221115420","DOIUrl":"https://doi.org/10.1177/10996362221115420","url":null,"abstract":"Disbond damage growth in honeycomb cored sandwich structures due to static and fatigue mixed mode loading is investigated numerically and experimentally. A two dimensional finite element model was generated using core homogenization and the Crack Surface Displacement Extrapolation mode separation method, integrated into a fracture mechanics based analysis sub-routine to predict face/core interface fatigue crack propagation. The Cycle Jump technique was furthermore applied to accelerate fatigue analysis. Mixed mode fatigue characterization testing was conducted using Double Cantilever Beam specimens loaded with Uneven Bending Moments, generating a relationship between crack propagation rates and energy release rate amplitudes as a modified Paris Law, measured at three mode-mixity phase angles. The measured Paris laws were subsequently used as input data for the numerical fatigue model. The numerical model was validated against CFRP/Nomex® Sandwich Tearing Test specimen tests with a propagating face/core interface crack yielding varying mode-mixities. The results from the validation showed good agreement between numerical predictions and experimental measurements.","PeriodicalId":17215,"journal":{"name":"Journal of Sandwich Structures & Materials","volume":"25 1","pages":"23 - 43"},"PeriodicalIF":3.9,"publicationDate":"2022-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42090521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-15DOI: 10.1177/10996362221114906
M. D. de Moura, R. Moreira, R. Rocha, Cristiana FM Oliveira
The asymmetric double cantilever beam (ADCB) test was used to measure the fracture energy of a honeycomb/carbon-epoxy sandwich panel under mode I loading. A data reduction scheme based on equivalent crack length theory was developed for this case. The experimental Resistance-curves were obtained using exclusively data ensuing from the load-displacement curves avoiding the usual and non-rigorous crack length monitoring during the test. Furthermore, a mode partitioning methodology lying on cohesive zone modelling was adopted, aiming to estimate the fracture energy under mode I loading from the total fracture energy under mixed-mode I+II ensuing from the ADCB test. Numerical simulations of the ADCB test considering cohesive zone modelling were performed for the sake of validation of the followed procedure.
{"title":"Determination of the fracture energy under mode I loading of a honeycomb/carbon-epoxy sandwich panel using the asymmetric double cantilever beam test","authors":"M. D. de Moura, R. Moreira, R. Rocha, Cristiana FM Oliveira","doi":"10.1177/10996362221114906","DOIUrl":"https://doi.org/10.1177/10996362221114906","url":null,"abstract":"The asymmetric double cantilever beam (ADCB) test was used to measure the fracture energy of a honeycomb/carbon-epoxy sandwich panel under mode I loading. A data reduction scheme based on equivalent crack length theory was developed for this case. The experimental Resistance-curves were obtained using exclusively data ensuing from the load-displacement curves avoiding the usual and non-rigorous crack length monitoring during the test. Furthermore, a mode partitioning methodology lying on cohesive zone modelling was adopted, aiming to estimate the fracture energy under mode I loading from the total fracture energy under mixed-mode I+II ensuing from the ADCB test. Numerical simulations of the ADCB test considering cohesive zone modelling were performed for the sake of validation of the followed procedure.","PeriodicalId":17215,"journal":{"name":"Journal of Sandwich Structures & Materials","volume":"24 1","pages":"1977 - 1992"},"PeriodicalIF":3.9,"publicationDate":"2022-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42581137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-13DOI: 10.1177/10996362221115418
Jacob I. Rome, V. Goyal, D. Patel
Discontinuities in foam-core composite sandwich panels are challenging to assess, in part due to shortcomings in the fundamental understanding of failure processes occurring in the foam. Extensive testing and analysis are frequently required to overcome this lack of understanding when evaluating large-scale structures. This integrated experimental and analytical study investigates the effect of core thickness mismatches on the load carrying capabilities of composite sandwich structures. These mismatches are commonly found in large composite components in aerospace, marine, automotive and other industries and can cause major reductions in sandwich shear strength. Mismatches result from joints between separate pieces of foam core within the sandwich, becoming potential failure initiation sites. Quantifying the reduction in shear strength is difficult due to the complex interaction between the facesheets, butt-joints and core. Sandwich structures containing butt joints are investigated through a research effort that included fabrication, testing, analysis, and nondestructive evaluations. The strength reduction of sandwich beams due to the presence of butt joints is quantified via three-point bend (3PTB) testing for various types of mismatches such as height and thickness of the butt joint. Key mechanical properties of the foam and the lamina are measured through testing and incorporated into analytical models. A stress area approach is proposed as a failure criterion, as test results show this to be promising in predicting the strength reductions measured in the 3PTB testing and the failure initiation site.
{"title":"Strength reduction of foam-core sandwich structures with core mismatches","authors":"Jacob I. Rome, V. Goyal, D. Patel","doi":"10.1177/10996362221115418","DOIUrl":"https://doi.org/10.1177/10996362221115418","url":null,"abstract":"Discontinuities in foam-core composite sandwich panels are challenging to assess, in part due to shortcomings in the fundamental understanding of failure processes occurring in the foam. Extensive testing and analysis are frequently required to overcome this lack of understanding when evaluating large-scale structures. This integrated experimental and analytical study investigates the effect of core thickness mismatches on the load carrying capabilities of composite sandwich structures. These mismatches are commonly found in large composite components in aerospace, marine, automotive and other industries and can cause major reductions in sandwich shear strength. Mismatches result from joints between separate pieces of foam core within the sandwich, becoming potential failure initiation sites. Quantifying the reduction in shear strength is difficult due to the complex interaction between the facesheets, butt-joints and core. Sandwich structures containing butt joints are investigated through a research effort that included fabrication, testing, analysis, and nondestructive evaluations. The strength reduction of sandwich beams due to the presence of butt joints is quantified via three-point bend (3PTB) testing for various types of mismatches such as height and thickness of the butt joint. Key mechanical properties of the foam and the lamina are measured through testing and incorporated into analytical models. A stress area approach is proposed as a failure criterion, as test results show this to be promising in predicting the strength reductions measured in the 3PTB testing and the failure initiation site.","PeriodicalId":17215,"journal":{"name":"Journal of Sandwich Structures & Materials","volume":"25 1","pages":"44 - 60"},"PeriodicalIF":3.9,"publicationDate":"2022-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46892445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-11DOI: 10.1177/10996362221115050
Huseyin E Yalkin, R. Karakuzu, Tuba Alpyildiz
In this study, various structural configurations such plain core, two-core, epoxy columns in the core, core stitched, and facesheet stitched were designed in the foam core sandwich composite with the aim to increase the absorbed energy and to decrease core/facesheet debonding area due to low-velocity impact. Glass fiber/epoxy and PVC foam were used as a facesheet material and a core material, respectively. The impact energy values were selected considering to penetration and perforation cases. The core stitching effect on low velocity impact behavior of sandwich composites were compared to facesheet stitching and it has been determined that the core stitching process can be an alternative to the facesheet stitching process in terms of the absorbed energy value. Impacted sandwich composites are investigated for core/facesheet debonding; the modifications through the thickness increased the failure path for core/facesheet debonding initiation and the results show that a significant decrease in the core/facesheet debonding area has been achieved.
{"title":"Low velocity impact behavior of sandwich composites with different structural configurations of foam core: An experimental study","authors":"Huseyin E Yalkin, R. Karakuzu, Tuba Alpyildiz","doi":"10.1177/10996362221115050","DOIUrl":"https://doi.org/10.1177/10996362221115050","url":null,"abstract":"In this study, various structural configurations such plain core, two-core, epoxy columns in the core, core stitched, and facesheet stitched were designed in the foam core sandwich composite with the aim to increase the absorbed energy and to decrease core/facesheet debonding area due to low-velocity impact. Glass fiber/epoxy and PVC foam were used as a facesheet material and a core material, respectively. The impact energy values were selected considering to penetration and perforation cases. The core stitching effect on low velocity impact behavior of sandwich composites were compared to facesheet stitching and it has been determined that the core stitching process can be an alternative to the facesheet stitching process in terms of the absorbed energy value. Impacted sandwich composites are investigated for core/facesheet debonding; the modifications through the thickness increased the failure path for core/facesheet debonding initiation and the results show that a significant decrease in the core/facesheet debonding area has been achieved.","PeriodicalId":17215,"journal":{"name":"Journal of Sandwich Structures & Materials","volume":"24 1","pages":"1941 - 1960"},"PeriodicalIF":3.9,"publicationDate":"2022-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44698576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-11DOI: 10.1177/10996362221115049
Raja Ouled Ahmed Ben Ali, Dorra Ben Abdeljelil, S. Chatti
This study presents experimental results and analysis of failure of sandwich beams with steel face sheets and polyurethane core tested in three-point bending. Firstly, a series of experiences are conducted in order to obtain the mechanical properties of the metallic face sheets and the foam core. To model the foam behavior, quasi-cyclic tests were performed by increasing the punch stroke. An exponential model is proposed describing the variation of the elastic modulus as a function of the strain. Secondly, the quasi-static and quasi-cyclic bending tests are carried out leading to failure of the sandwich beam. The results of the quasi-cyclic bending show that the behavior of the sandwich beam is similar to the foam behavior in quasi-cyclic compression. Thirdly, a Finite Element Analysis (FEA) is performed in order to predict the observed foam fracture in bending test using a shear damage criterion for the foam core. The comparisons show a satisfactory agreement between the experimental results and the FEA predictions.
{"title":"Failure initiation and progression of sandwich beams under cyclic bending tests","authors":"Raja Ouled Ahmed Ben Ali, Dorra Ben Abdeljelil, S. Chatti","doi":"10.1177/10996362221115049","DOIUrl":"https://doi.org/10.1177/10996362221115049","url":null,"abstract":"This study presents experimental results and analysis of failure of sandwich beams with steel face sheets and polyurethane core tested in three-point bending. Firstly, a series of experiences are conducted in order to obtain the mechanical properties of the metallic face sheets and the foam core. To model the foam behavior, quasi-cyclic tests were performed by increasing the punch stroke. An exponential model is proposed describing the variation of the elastic modulus as a function of the strain. Secondly, the quasi-static and quasi-cyclic bending tests are carried out leading to failure of the sandwich beam. The results of the quasi-cyclic bending show that the behavior of the sandwich beam is similar to the foam behavior in quasi-cyclic compression. Thirdly, a Finite Element Analysis (FEA) is performed in order to predict the observed foam fracture in bending test using a shear damage criterion for the foam core. The comparisons show a satisfactory agreement between the experimental results and the FEA predictions.","PeriodicalId":17215,"journal":{"name":"Journal of Sandwich Structures & Materials","volume":"24 1","pages":"1961 - 1976"},"PeriodicalIF":3.9,"publicationDate":"2022-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44985731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, theoretical analysis, numerical simulation and mechanical test on the 3D printed lattice sandwich structures are carried out to study the buckling performance. 2 types of lattice structures, body centered cubic (BCC) and rhombic dodecahedron (DOD) are included. The lattice sandwich panels are made of ALSi10 Mg alloy materials and manufactured using the selective laser melting technique. The comparative results show that DOD lattice sandwich panel not only has higher bearing capacity, but also shows stronger toughness in the post-buckling stage than BCC type panel, even they have the same characteristic size. The buckling mode depends on the topology of the unit cell. For BCC and DOD type panels, the main buckling modes are local buckling and global buckling respectively. The reasons of different buckling modes are discussed. Moreover, the buckling evolution and failure modes of the two types of panels in the post-buckling stage are investigated.
{"title":"Experimental and numerical investigation on the buckling of 3D printed sandwich structure with lattice core","authors":"Yiqun Cao, Xiaoliang Geng, Hui Han, Yahui Lu, J. Wang, Changan Zhao","doi":"10.1177/10996362221108974","DOIUrl":"https://doi.org/10.1177/10996362221108974","url":null,"abstract":"In this paper, theoretical analysis, numerical simulation and mechanical test on the 3D printed lattice sandwich structures are carried out to study the buckling performance. 2 types of lattice structures, body centered cubic (BCC) and rhombic dodecahedron (DOD) are included. The lattice sandwich panels are made of ALSi10 Mg alloy materials and manufactured using the selective laser melting technique. The comparative results show that DOD lattice sandwich panel not only has higher bearing capacity, but also shows stronger toughness in the post-buckling stage than BCC type panel, even they have the same characteristic size. The buckling mode depends on the topology of the unit cell. For BCC and DOD type panels, the main buckling modes are local buckling and global buckling respectively. The reasons of different buckling modes are discussed. Moreover, the buckling evolution and failure modes of the two types of panels in the post-buckling stage are investigated.","PeriodicalId":17215,"journal":{"name":"Journal of Sandwich Structures & Materials","volume":"24 1","pages":"1923 - 1940"},"PeriodicalIF":3.9,"publicationDate":"2022-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45919908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-08DOI: 10.1177/10996362221106782
V. Goyal, Jacob I. Rome, D. Patel
An experimental test program and companion analytical study were designed and conducted to gain understanding of the tensile failure mechanisms in asymmetrical tapered sandwich core structures at cold temperatures. Representative test coupons were subjected to a tensile load in an environmental chamber to induce foam tensile failure in the core. Finite-element modeling with a proposed maximum principal stress criterion was used to predict the failure loads of the tapered test coupon design at the test temperatures. The predicted failure loads were in good agreement with test results. An important finding is that the cure stresses in the foam are significant and should not be ignored. Additionally, the analysis correctly predicted the failure initiation location, which was verified using high speed photography during the tensile test. The study identified the critical failure regions of asymmetrical tapered sandwich core designs and the failure load dependence on the temperature gradient in the structure.
{"title":"Strength of asymmetric tapered composite foam core sandwich structures subjected to thermomechanical loading","authors":"V. Goyal, Jacob I. Rome, D. Patel","doi":"10.1177/10996362221106782","DOIUrl":"https://doi.org/10.1177/10996362221106782","url":null,"abstract":"An experimental test program and companion analytical study were designed and conducted to gain understanding of the tensile failure mechanisms in asymmetrical tapered sandwich core structures at cold temperatures. Representative test coupons were subjected to a tensile load in an environmental chamber to induce foam tensile failure in the core. Finite-element modeling with a proposed maximum principal stress criterion was used to predict the failure loads of the tapered test coupon design at the test temperatures. The predicted failure loads were in good agreement with test results. An important finding is that the cure stresses in the foam are significant and should not be ignored. Additionally, the analysis correctly predicted the failure initiation location, which was verified using high speed photography during the tensile test. The study identified the critical failure regions of asymmetrical tapered sandwich core designs and the failure load dependence on the temperature gradient in the structure.","PeriodicalId":17215,"journal":{"name":"Journal of Sandwich Structures & Materials","volume":"25 1","pages":"6 - 22"},"PeriodicalIF":3.9,"publicationDate":"2022-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47040840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-01DOI: 10.1177/10996362221106780
Chao Zhou, Zhuofan Ni, Xinran Zheng, Bo Wang, Rui Li
In this paper, the first attempt is made to obtain some new analytic free vibration solutions of rectangular sandwich panels within the symplectic solution framework, which are difficult to tackle within the conventional analytic solution framework. The sandwich panels with honeycomb and truss cores are first treated as equivalent thick plates. The governing dual equation is then established within the Hamiltonian system. Subsequently, the original problem is converted into two subproblems whose analytic solutions are acquired by applying the variable separation and symplectic eigen expansion. The superposition yields the final analytic free vibration solution, with the emerging coefficients determined according to the equivalence between the original problem and the superposition. The natural frequency and mode shape solutions by the present symplectic superposition method are quantitatively shown via numerical and graphical results, respectively, and are all well validated by consistency with classical solutions, experimental results, or the numerical solutions by the refined finite element modeling. Besides providing the new results that can serve as benchmarks, the effects of the size parameters on the natural frequencies of the sandwich panels are also analyzed. Since the developed method gives up the assumption of any trial solutions and follows a rigorous derivation to yield new analytic solutions, it provides opportunities for solving more intricate problems of sandwich panels and shells.
{"title":"On new benchmark free vibration solutions of rectangular sandwich panels within the symplectic solution framework","authors":"Chao Zhou, Zhuofan Ni, Xinran Zheng, Bo Wang, Rui Li","doi":"10.1177/10996362221106780","DOIUrl":"https://doi.org/10.1177/10996362221106780","url":null,"abstract":"In this paper, the first attempt is made to obtain some new analytic free vibration solutions of rectangular sandwich panels within the symplectic solution framework, which are difficult to tackle within the conventional analytic solution framework. The sandwich panels with honeycomb and truss cores are first treated as equivalent thick plates. The governing dual equation is then established within the Hamiltonian system. Subsequently, the original problem is converted into two subproblems whose analytic solutions are acquired by applying the variable separation and symplectic eigen expansion. The superposition yields the final analytic free vibration solution, with the emerging coefficients determined according to the equivalence between the original problem and the superposition. The natural frequency and mode shape solutions by the present symplectic superposition method are quantitatively shown via numerical and graphical results, respectively, and are all well validated by consistency with classical solutions, experimental results, or the numerical solutions by the refined finite element modeling. Besides providing the new results that can serve as benchmarks, the effects of the size parameters on the natural frequencies of the sandwich panels are also analyzed. Since the developed method gives up the assumption of any trial solutions and follows a rigorous derivation to yield new analytic solutions, it provides opportunities for solving more intricate problems of sandwich panels and shells.","PeriodicalId":17215,"journal":{"name":"Journal of Sandwich Structures & Materials","volume":"24 1","pages":"1883 - 1904"},"PeriodicalIF":3.9,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45791709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-01DOI: 10.1177/10996362221108973
Alparslan Solak, B. A. Temiztas, Berna Bolat
Sandwich structures are frequently used in structural areas where lightness and strength are essential. These structures are indispensable for sailing boats, and ground and air vehicles. The base purpose of this study is to investigate the effect of wave parameters on the sandwich structure. The data obtained from the bending tests of the model created using Ls-Dyna was compared with the experimental data of the literature. There is a 3.05% difference between the peak force in experimental and Ls-Dyna. The force-deformation plots are coherent, and the progressive images of the sandwich structure during bending are similar. In addition, using theoretical approaches, the highest force and the amount of collapse during bending were determined. There is a difference of 3.1% between the theoretical approach and Ls-Dyna values. Thus, the Ls-Dyna model was validated. The flat cell walls of the honeycomb were modeled as a sine wave. Four wave numbers and wave amplitudes were used. In this way, 16 different analysis files were created. The results show that the new sandwich structure’s specific peak force and specific energy absorption (SEA) increased by 7–110% compared to the ordinary flat walled sandwich structure. This research will assist in the design of new sandwich structures.
{"title":"Investigation of the effect of wavy honeycomb on the bending performance of the sandwich structure","authors":"Alparslan Solak, B. A. Temiztas, Berna Bolat","doi":"10.1177/10996362221108973","DOIUrl":"https://doi.org/10.1177/10996362221108973","url":null,"abstract":"Sandwich structures are frequently used in structural areas where lightness and strength are essential. These structures are indispensable for sailing boats, and ground and air vehicles. The base purpose of this study is to investigate the effect of wave parameters on the sandwich structure. The data obtained from the bending tests of the model created using Ls-Dyna was compared with the experimental data of the literature. There is a 3.05% difference between the peak force in experimental and Ls-Dyna. The force-deformation plots are coherent, and the progressive images of the sandwich structure during bending are similar. In addition, using theoretical approaches, the highest force and the amount of collapse during bending were determined. There is a difference of 3.1% between the theoretical approach and Ls-Dyna values. Thus, the Ls-Dyna model was validated. The flat cell walls of the honeycomb were modeled as a sine wave. Four wave numbers and wave amplitudes were used. In this way, 16 different analysis files were created. The results show that the new sandwich structure’s specific peak force and specific energy absorption (SEA) increased by 7–110% compared to the ordinary flat walled sandwich structure. This research will assist in the design of new sandwich structures.","PeriodicalId":17215,"journal":{"name":"Journal of Sandwich Structures & Materials","volume":"24 1","pages":"1905 - 1919"},"PeriodicalIF":3.9,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46116729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-18DOI: 10.1177/10996362221101139
Bin Li, Tao Fu
The main objective of this research work is focused on the vibration analysis of auxetic sandwich cylindrical shell structures resting on an elastic foundation. In the analysis, the sandwich shell structure is composed of three layers in which the middle layer consists of auxetic material with a negative Poisson’s ratio, and the two skin layers are isotropic homogeneous materials. The motion equation is extracted according to the first-order shear deformation theory (FSDT) and the Hamilton principle. The governing equations of coupled partial differential equations are solved by the generalized differential quadrature (GDQ) method, and the natural frequencies are determined. By comparing the experimental results with the numerical results calculated by commercial finite element software, the validity of the proposed theoretical model is verified. Finally, the influences of geometrical parameters and elastic foundation on the vibration behavior of sandwich shell structures have been investigated.
{"title":"Analysis of vibration characteristics of auxetic sandwich cylindrical shells resting on elastic foundation","authors":"Bin Li, Tao Fu","doi":"10.1177/10996362221101139","DOIUrl":"https://doi.org/10.1177/10996362221101139","url":null,"abstract":"The main objective of this research work is focused on the vibration analysis of auxetic sandwich cylindrical shell structures resting on an elastic foundation. In the analysis, the sandwich shell structure is composed of three layers in which the middle layer consists of auxetic material with a negative Poisson’s ratio, and the two skin layers are isotropic homogeneous materials. The motion equation is extracted according to the first-order shear deformation theory (FSDT) and the Hamilton principle. The governing equations of coupled partial differential equations are solved by the generalized differential quadrature (GDQ) method, and the natural frequencies are determined. By comparing the experimental results with the numerical results calculated by commercial finite element software, the validity of the proposed theoretical model is verified. Finally, the influences of geometrical parameters and elastic foundation on the vibration behavior of sandwich shell structures have been investigated.","PeriodicalId":17215,"journal":{"name":"Journal of Sandwich Structures & Materials","volume":"24 1","pages":"1865 - 1882"},"PeriodicalIF":3.9,"publicationDate":"2022-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45988172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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