ABSTRACT In this study, an SiO2/epoxy adhesive that can be cured in a wet/water environment was prepared. Nonisothermal differential scanning calorimetry was used to evaluate the curing reaction of this adhesive. Kinetic parameters of the adhesive were obtained using the Kissinger, Ozawa, Flynn–Wall–Ozawa, and Kissinger–Akahira–Sunose methods. The results show that the isoconversional methods can well explain the curing behavior of SiO2/epoxy adhesive. Further, the tensile lap-shear strength of the prepared adhesive cured in air and water increased by 35.96% and 32.07% than pure epoxy adhesive, respectively. Although the presence of water molecules affects the bond strength of the SiO2/epoxy adhesive, its bond strength underwater was only 1.45 MPa lower than that in air. Compared to the pure epoxy resin, the tensile and flexural strength of SiO2/epoxy adhesive cured in air were 12.23%, 6.67% higher and those of the adhesive cured in water were 10.24% and 6.62% higher, respectively. Compared to the pure epoxy resin, the tensile and flexural modulus of SiO2/epoxy adhesive cured in air increased by 13.71%, 10.25% and those of the adhesive cured in water increased by 11.21% and 10.41%, respectively.
{"title":"Curing kinetics and mechanical properties of an underwater SiO2/epoxy adhesive","authors":"Xiaodong Wang, Xin Zhang, Xiaotian Bian, Chenchen Lu, Qi Li, Chengying Bai, Lili Zhang, Ting Zheng","doi":"10.1080/00218464.2022.2151906","DOIUrl":"https://doi.org/10.1080/00218464.2022.2151906","url":null,"abstract":"ABSTRACT In this study, an SiO2/epoxy adhesive that can be cured in a wet/water environment was prepared. Nonisothermal differential scanning calorimetry was used to evaluate the curing reaction of this adhesive. Kinetic parameters of the adhesive were obtained using the Kissinger, Ozawa, Flynn–Wall–Ozawa, and Kissinger–Akahira–Sunose methods. The results show that the isoconversional methods can well explain the curing behavior of SiO2/epoxy adhesive. Further, the tensile lap-shear strength of the prepared adhesive cured in air and water increased by 35.96% and 32.07% than pure epoxy adhesive, respectively. Although the presence of water molecules affects the bond strength of the SiO2/epoxy adhesive, its bond strength underwater was only 1.45 MPa lower than that in air. Compared to the pure epoxy resin, the tensile and flexural strength of SiO2/epoxy adhesive cured in air were 12.23%, 6.67% higher and those of the adhesive cured in water were 10.24% and 6.62% higher, respectively. Compared to the pure epoxy resin, the tensile and flexural modulus of SiO2/epoxy adhesive cured in air increased by 13.71%, 10.25% and those of the adhesive cured in water increased by 11.21% and 10.41%, respectively.","PeriodicalId":14778,"journal":{"name":"Journal of Adhesion","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49592779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2022-11-23DOI: 10.1080/00218464.2022.2149325
Zhongjie Yue, Qiuren Chen, Li Huang, Yudong Fang, Mushi Li, Shiyao Huang, Hailong Zhao, Zuguo Bao, Xianhui Wang, Weijian Han
ABSTRACT An integrated adhesive material model calibration method is proposed for adhesively bonded joints’ deformation and progressive failure simulations under mixed loading modes. In this method, a surrogate model is trained to express the intrinsic numerical relationship between the key parameters (e.g., the yield normal stress and yield shear stress) and the simulated load-displacement curves of the bonded specimens. The parameter calibration process of the material model under multiple loading conditions is described as a multi-objective optimization problem. To minimize the load-displacement curve errors among the CAE simulation model and the experiment data, the model parameters are calibrated effectively based on the surrogate model using the genetic algorithm. The validity and efficiency of the proposed calibration method is verified by comparing the test data under various loading conditions. The better precision and efficiency indicates the potential of using this framework to effectively calibrate material properties without performing time-consuming CAE simulations.
{"title":"A surrogate model based calibration method for structural adhesive joint progressive failure simulations","authors":"Zhongjie Yue, Qiuren Chen, Li Huang, Yudong Fang, Mushi Li, Shiyao Huang, Hailong Zhao, Zuguo Bao, Xianhui Wang, Weijian Han","doi":"10.1080/00218464.2022.2149325","DOIUrl":"https://doi.org/10.1080/00218464.2022.2149325","url":null,"abstract":"ABSTRACT An integrated adhesive material model calibration method is proposed for adhesively bonded joints’ deformation and progressive failure simulations under mixed loading modes. In this method, a surrogate model is trained to express the intrinsic numerical relationship between the key parameters (e.g., the yield normal stress and yield shear stress) and the simulated load-displacement curves of the bonded specimens. The parameter calibration process of the material model under multiple loading conditions is described as a multi-objective optimization problem. To minimize the load-displacement curve errors among the CAE simulation model and the experiment data, the model parameters are calibrated effectively based on the surrogate model using the genetic algorithm. The validity and efficiency of the proposed calibration method is verified by comparing the test data under various loading conditions. The better precision and efficiency indicates the potential of using this framework to effectively calibrate material properties without performing time-consuming CAE simulations.","PeriodicalId":14778,"journal":{"name":"Journal of Adhesion","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44356890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2022-11-15DOI: 10.1080/00218464.2022.2144732
Fernando Madureira, L. D. da Silva, V. Tita
ABSTRACT The present work investigates the equivalent crack methodology by considering the Double Cantilever Beam (DCB) test to obtain the strain energy release rate of adhesive joints, using different compliance methods rather than the Compliance Based Beam Model (CBBM). This procedure allows the determination of the crack length based on the compliance of the specimen, which avoids crack growth monitoring during tests. The compliance values predicted by the analytical methods were studied and compared with a computational model, considering different crack lengths. Results showed that the preciseness of the crack length obtained by the equivalent crack method relies on the accuracy of the respective compliance method in predicting the load-displacement curve of a bonded double cantilever beam. The Euler–Bernoulli and Timoshenko beam models are not recommended to obtain an equivalent crack length based on the specimen’s compliance since they overestimate the actual crack length. Best crack length predictions were obtained using compliance methods based on the beam-on-elastic foundation models, including an elastic interface to model the adhesive layer joint. Similar strain energy release rate results were found for different compliance methods when using the equivalent crack methodology.
{"title":"Compliance Methods For Bonded Joints: Part II - Investigation Of The Equivalent Crack Methodology To Obtain The Strain Energy Release Rate For Mode I","authors":"Fernando Madureira, L. D. da Silva, V. Tita","doi":"10.1080/00218464.2022.2144732","DOIUrl":"https://doi.org/10.1080/00218464.2022.2144732","url":null,"abstract":"ABSTRACT The present work investigates the equivalent crack methodology by considering the Double Cantilever Beam (DCB) test to obtain the strain energy release rate of adhesive joints, using different compliance methods rather than the Compliance Based Beam Model (CBBM). This procedure allows the determination of the crack length based on the compliance of the specimen, which avoids crack growth monitoring during tests. The compliance values predicted by the analytical methods were studied and compared with a computational model, considering different crack lengths. Results showed that the preciseness of the crack length obtained by the equivalent crack method relies on the accuracy of the respective compliance method in predicting the load-displacement curve of a bonded double cantilever beam. The Euler–Bernoulli and Timoshenko beam models are not recommended to obtain an equivalent crack length based on the specimen’s compliance since they overestimate the actual crack length. Best crack length predictions were obtained using compliance methods based on the beam-on-elastic foundation models, including an elastic interface to model the adhesive layer joint. Similar strain energy release rate results were found for different compliance methods when using the equivalent crack methodology.","PeriodicalId":14778,"journal":{"name":"Journal of Adhesion","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42215609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2022-11-15DOI: 10.1080/00218464.2022.2144731
Fernando Madureira, L. D. da Silva, V. Tita
ABSTRACT The double cantilever beam (DCB) is the most acceptable geometry to obtain the critical strain energy release rate (GIc ) of adhesive joints under Mode I. However, there are still some areas of uncertainty in the standardized compliance methods recommended by the ISO and ASTM standards in terms of accuracy in estimating the compliance of a bonded double cantilever beam and, consequently, GIc . In this work, an investigation of the standardized compliance methods for fracture characterization of bonded joints under Mode I is conducted, employing a finite element model to obtain the compliance of a double cantilever beam, considering different crack lengths. The compliance values determined from the finite element model are compared with those recommended by the standards. It is concluded that the standardized compliance methods are very sensitive to issues derived from crack length measurements. The crack length correction methodology proposed by the corrected beam theory is inadequate, which can lead to a wrong interpretation of the structure’s behavior and the structural integrity assessment. The best approach to obtain the compliance of a double cantilever beam in respect of crack length is to use a compliance calibration method, fitting an expression for the experimental curve.
{"title":"Compliance Methods For Bonded Joints: Part I - Investigation Of The Standardized Methods To Obtain The Strain Energy Release Rate For Mode I","authors":"Fernando Madureira, L. D. da Silva, V. Tita","doi":"10.1080/00218464.2022.2144731","DOIUrl":"https://doi.org/10.1080/00218464.2022.2144731","url":null,"abstract":"ABSTRACT The double cantilever beam (DCB) is the most acceptable geometry to obtain the critical strain energy release rate (GIc ) of adhesive joints under Mode I. However, there are still some areas of uncertainty in the standardized compliance methods recommended by the ISO and ASTM standards in terms of accuracy in estimating the compliance of a bonded double cantilever beam and, consequently, GIc . In this work, an investigation of the standardized compliance methods for fracture characterization of bonded joints under Mode I is conducted, employing a finite element model to obtain the compliance of a double cantilever beam, considering different crack lengths. The compliance values determined from the finite element model are compared with those recommended by the standards. It is concluded that the standardized compliance methods are very sensitive to issues derived from crack length measurements. The crack length correction methodology proposed by the corrected beam theory is inadequate, which can lead to a wrong interpretation of the structure’s behavior and the structural integrity assessment. The best approach to obtain the compliance of a double cantilever beam in respect of crack length is to use a compliance calibration method, fitting an expression for the experimental curve.","PeriodicalId":14778,"journal":{"name":"Journal of Adhesion","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46912499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2022-11-14DOI: 10.1080/00218464.2022.2147832
Yi Li, Ruizhi Ding, Shaoqiang Wang, Jicai Liang, Weiguo Yao
ABSTRACT Bonding technology is used as the main connection mode of coated structures of car interior trim, of which the process and structure are being continuously optimized. In this paper, ABAQUS software is applied to establish the finite element model of the bonded structure of the dash panel. Based on the cohesive zone model (CZM) method, the damage and failure process of surface joints under different displacement loading conditions are numerically simulated. The effectiveness of the finite element model based on CZM for the numerical simulation of the damage and failure processes of bonded surface joints is verified from the perspectives of the numerical calculation method, experimental verification, and numerical result analysis. The results show that the finite element model based on CZM theory can effectively simulate and evaluate the damage and failure processes of multiphase polymers or composite surface joints. By obtaining the load‒displacement curves, the stress nephogram and the damage nephogram, the dynamic processes of damage initiation, damage evolution and failure of the surface joint are observed and analysed, and the bonding strength of the interlayer model is also compared and analysed. Compared with the bonding interface between the skin and cloth, the bonding interface between the frame and cloth is less prone to damage.
{"title":"Effectiveness analysis of the study on the bonding performance of car soft decoration coated interior trim based on cohesive zone model","authors":"Yi Li, Ruizhi Ding, Shaoqiang Wang, Jicai Liang, Weiguo Yao","doi":"10.1080/00218464.2022.2147832","DOIUrl":"https://doi.org/10.1080/00218464.2022.2147832","url":null,"abstract":"ABSTRACT Bonding technology is used as the main connection mode of coated structures of car interior trim, of which the process and structure are being continuously optimized. In this paper, ABAQUS software is applied to establish the finite element model of the bonded structure of the dash panel. Based on the cohesive zone model (CZM) method, the damage and failure process of surface joints under different displacement loading conditions are numerically simulated. The effectiveness of the finite element model based on CZM for the numerical simulation of the damage and failure processes of bonded surface joints is verified from the perspectives of the numerical calculation method, experimental verification, and numerical result analysis. The results show that the finite element model based on CZM theory can effectively simulate and evaluate the damage and failure processes of multiphase polymers or composite surface joints. By obtaining the load‒displacement curves, the stress nephogram and the damage nephogram, the dynamic processes of damage initiation, damage evolution and failure of the surface joint are observed and analysed, and the bonding strength of the interlayer model is also compared and analysed. Compared with the bonding interface between the skin and cloth, the bonding interface between the frame and cloth is less prone to damage.","PeriodicalId":14778,"journal":{"name":"Journal of Adhesion","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41746662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2022-11-11DOI: 10.1080/00218464.2022.2141626
Youguo Wang, Xiaorong Wang
ABSTRACT In the present work, the tack properties of a number of uncrosslinked polymers, oil-extended rubbers and particle-filled elastomers to a metal surface were investigated by first contacting a cylindrical metal probe with a flat-ended surface with an elastomer surface and then detaching the probe from the adhered substrate at various separation speeds. Our results reveal that there are simple and universal laws governing the tackiness behavior of these materials. Specifically, when the pulling speed (Vs ) is greater than a critical speed (Vc ), the maximum tack force (Fmax ) can be generally described by the following scaling relationships: Fma x ~ Vs 1/3 and Fmax ~ tmax −1/2, where tmax is the time when the maximum force is reached in the force-time profile. The chemical composition, polymer structure, plasticizer type and filler type in a rubber compound can affect the magnitude of the tacky force at a given separation speed, but have little or no effect on these scaling relationships that primarily exist at high separation speeds.
{"title":"The dependence of rubber tackiness on separation speed","authors":"Youguo Wang, Xiaorong Wang","doi":"10.1080/00218464.2022.2141626","DOIUrl":"https://doi.org/10.1080/00218464.2022.2141626","url":null,"abstract":"ABSTRACT In the present work, the tack properties of a number of uncrosslinked polymers, oil-extended rubbers and particle-filled elastomers to a metal surface were investigated by first contacting a cylindrical metal probe with a flat-ended surface with an elastomer surface and then detaching the probe from the adhered substrate at various separation speeds. Our results reveal that there are simple and universal laws governing the tackiness behavior of these materials. Specifically, when the pulling speed (Vs ) is greater than a critical speed (Vc ), the maximum tack force (Fmax ) can be generally described by the following scaling relationships: Fma x ~ Vs 1/3 and Fmax ~ tmax −1/2, where tmax is the time when the maximum force is reached in the force-time profile. The chemical composition, polymer structure, plasticizer type and filler type in a rubber compound can affect the magnitude of the tacky force at a given separation speed, but have little or no effect on these scaling relationships that primarily exist at high separation speeds.","PeriodicalId":14778,"journal":{"name":"Journal of Adhesion","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42023238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2022-10-31DOI: 10.1080/00218464.2022.2141114
Guofeng Qin, Guoshuai Li, Peiwen Mi, Yongjian Zhu, Ming Li, Jingxin Na
ABSTRACT To systematically and comprehensively analyze the effects of different aging environments on the aging failure of aluminum alloy/CFRP (Carbon Fiber Reinforced Plastics) composite bonded shear and butt joints, seven typical aging environments of room temperature (23°C/20%RH, RT), high-temperature (80°C/20%RH, HT), low temperature (−40°C, LT), temperature cycles (−40 ~ 80°C/20%RH, TC), immersed in water at room temperature (IRT), high temperature and high humidity (80°C /95%RH, HTHH), and hygrothermal cycles (−40°C ~ 80°C /95%RH, HC) were selected to perform aging tests. The composition analysis revealed that the adhesive underwent the most significant post-curing in HT, followed by TC, while LT had almost no effect on the adhesive. It was also found that the degree of moisture absorption and hydrolysis of the adhesive in IRT, HTHH and HC decreased sequentially. A single temperature or humidity environment had small effect on the failure strength of bonded joints less than 20%, increasing temperature or humidity could further reduce the failure strength by about 30%, and periodically changing the temperature or humidity had the greatest effect on the failure strength by more than 40%. ANOVA (Analysis of Variance) shows that all the single factors of aging time, load type, or aging environment had significant effects on the failure strength, but the aging environment had the greatest effect. Multifactor coupling effects on the failure strength was not significant, except for the coupling effects of aging environment and aging time.
{"title":"A systematic study on the failure behaviors of aluminum alloy /composite bonded joints exposed to various typical aging environments for automobiles","authors":"Guofeng Qin, Guoshuai Li, Peiwen Mi, Yongjian Zhu, Ming Li, Jingxin Na","doi":"10.1080/00218464.2022.2141114","DOIUrl":"https://doi.org/10.1080/00218464.2022.2141114","url":null,"abstract":"ABSTRACT To systematically and comprehensively analyze the effects of different aging environments on the aging failure of aluminum alloy/CFRP (Carbon Fiber Reinforced Plastics) composite bonded shear and butt joints, seven typical aging environments of room temperature (23°C/20%RH, RT), high-temperature (80°C/20%RH, HT), low temperature (−40°C, LT), temperature cycles (−40 ~ 80°C/20%RH, TC), immersed in water at room temperature (IRT), high temperature and high humidity (80°C /95%RH, HTHH), and hygrothermal cycles (−40°C ~ 80°C /95%RH, HC) were selected to perform aging tests. The composition analysis revealed that the adhesive underwent the most significant post-curing in HT, followed by TC, while LT had almost no effect on the adhesive. It was also found that the degree of moisture absorption and hydrolysis of the adhesive in IRT, HTHH and HC decreased sequentially. A single temperature or humidity environment had small effect on the failure strength of bonded joints less than 20%, increasing temperature or humidity could further reduce the failure strength by about 30%, and periodically changing the temperature or humidity had the greatest effect on the failure strength by more than 40%. ANOVA (Analysis of Variance) shows that all the single factors of aging time, load type, or aging environment had significant effects on the failure strength, but the aging environment had the greatest effect. Multifactor coupling effects on the failure strength was not significant, except for the coupling effects of aging environment and aging time.","PeriodicalId":14778,"journal":{"name":"Journal of Adhesion","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43777120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2022-10-21DOI: 10.1080/00218464.2022.2138358
G.C.G. Serra, P. Reis, J. Ferreira
ABSTRACT Mixed adhesive joints combining different stiffnesses and strengths in the same overlap is a good strategy to increase the mechanical properties. For this purpose, different adhesives with distinct curing temperatures are used, whose optimization is crucial to maximize the mechanical performance. In this context, this study considers Araldite® AV 4076–1/HY 4076 and Araldite® AW 106/HV 953 U adhesives to evaluate the effect of curing temperature on tensile strength, creep and stress relaxation response and fatigue strength of single lap joints. It was possible to conclude that both adhesives exhibited higher static strength, lower stress relaxation and lower creep displacements with increasing curing temperature, but while for the brittle adhesive this trend occurred up to 150°C for the ductile one it was only up to 70°C. After this value, all properties regressed due to the degradation of the ductile adhesive with temperature. Considering values corresponding to 25% of the tensile strength, for example, it was noted that the ductile adhesive relaxes 54.7% more than the fragile one and presents a creep displacement around 95.1% higher. On the other hand, while the fatigue life was shown to be insensitive to the curing temperature for the brittle adhesive, in the case of the ductile one it decreases after 70°C. Therefore, when these adhesives are combined into a mixed adhesive joint, the curing temperature must never exceed 70°C.
{"title":"Effect of cure temperature on the mechanical properties of epoxy-aluminium single lap joints","authors":"G.C.G. Serra, P. Reis, J. Ferreira","doi":"10.1080/00218464.2022.2138358","DOIUrl":"https://doi.org/10.1080/00218464.2022.2138358","url":null,"abstract":"ABSTRACT Mixed adhesive joints combining different stiffnesses and strengths in the same overlap is a good strategy to increase the mechanical properties. For this purpose, different adhesives with distinct curing temperatures are used, whose optimization is crucial to maximize the mechanical performance. In this context, this study considers Araldite® AV 4076–1/HY 4076 and Araldite® AW 106/HV 953 U adhesives to evaluate the effect of curing temperature on tensile strength, creep and stress relaxation response and fatigue strength of single lap joints. It was possible to conclude that both adhesives exhibited higher static strength, lower stress relaxation and lower creep displacements with increasing curing temperature, but while for the brittle adhesive this trend occurred up to 150°C for the ductile one it was only up to 70°C. After this value, all properties regressed due to the degradation of the ductile adhesive with temperature. Considering values corresponding to 25% of the tensile strength, for example, it was noted that the ductile adhesive relaxes 54.7% more than the fragile one and presents a creep displacement around 95.1% higher. On the other hand, while the fatigue life was shown to be insensitive to the curing temperature for the brittle adhesive, in the case of the ductile one it decreases after 70°C. Therefore, when these adhesives are combined into a mixed adhesive joint, the curing temperature must never exceed 70°C.","PeriodicalId":14778,"journal":{"name":"Journal of Adhesion","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43864416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2022-10-12DOI: 10.1080/00218464.2022.2134012
Jakub Kawalerczyk, Joanna Walkiewicz, M. Woźniak, D. Dziurka, R. Mirski
ABSTRACT The aim of the study was to investigate the effect of propylamine addition to urea-formaldehyde resin on the properties of resultant plywood. The research consisted in investigating the properties of both liquid and cured resins, as well as the produced plywood. Studies have shown that the incorporation of propylamine adversely affected reactivity of the adhesive mixtures by increasing their pH. The evaluation of adhesive chemical structure with FTIR spectroscopy showed some slight changes indicating the reaction of formaldehyde with introduced modifier. The addition of propylamine contributed to the considerable reduction of free formaldehyde contained in the cured adhesive. Furthermore, the propylamine was also found to work effectively as a formaldehyde scavenger by significantly reducing the hazardous emission from plywood. However, based on the results of bonding quality, delamination, bending strength and modulus of elasticity it was found that application of propylamine resulted in a noticeable deterioration of plywood properties. Therefore, the amount of introduced modifier should not exceed 1% of solid UF resin.
{"title":"The effect of urea-formaldehyde adhesive modification with propylamine on the properties of manufactured plywood","authors":"Jakub Kawalerczyk, Joanna Walkiewicz, M. Woźniak, D. Dziurka, R. Mirski","doi":"10.1080/00218464.2022.2134012","DOIUrl":"https://doi.org/10.1080/00218464.2022.2134012","url":null,"abstract":"ABSTRACT The aim of the study was to investigate the effect of propylamine addition to urea-formaldehyde resin on the properties of resultant plywood. The research consisted in investigating the properties of both liquid and cured resins, as well as the produced plywood. Studies have shown that the incorporation of propylamine adversely affected reactivity of the adhesive mixtures by increasing their pH. The evaluation of adhesive chemical structure with FTIR spectroscopy showed some slight changes indicating the reaction of formaldehyde with introduced modifier. The addition of propylamine contributed to the considerable reduction of free formaldehyde contained in the cured adhesive. Furthermore, the propylamine was also found to work effectively as a formaldehyde scavenger by significantly reducing the hazardous emission from plywood. However, based on the results of bonding quality, delamination, bending strength and modulus of elasticity it was found that application of propylamine resulted in a noticeable deterioration of plywood properties. Therefore, the amount of introduced modifier should not exceed 1% of solid UF resin.","PeriodicalId":14778,"journal":{"name":"Journal of Adhesion","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43420541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT The wind turbine blade trailing edge (TE) is frequently exposed to compressive loading and can even be damaged under complex operating conditions. Among the most typical TE failure modes is the adhesive-joint failure, so it is necessary to evaluate the structural behavior of the adhesive joints in TE under compressive loading. In this regard, an improved testing method was proposed for blade subcomponents. Specifically, the experiment was performed on a composite TE structural specimen under compressive loading to reveal its internal failure mechanism. The results showed that when the TE specimen was compressed under increasing load, buckling deformation occurred gradually at the sandwich laminates. Also, the bending deformations of the laminates on the suction and pressure sides were different in the bonding region. The resultant shearing effect led to the structural adhesive undergoing brittle fracture, which then triggered debonding and extension, finally causing the debonding failure of the trailing-edge specimen. To guarantee the safety of a blade under edge-wise loading, it is suggested that the structural strength of the TE should be emphasized during the blade design process.
{"title":"Experimental research on the compression failure of wind turbine blade trailing edge structure","authors":"Honghui Wu, Liangwen Qi, Jing Qian, Huijing Cao, Kezhong Shi, Jianzhong Xu","doi":"10.1080/00218464.2022.2126313","DOIUrl":"https://doi.org/10.1080/00218464.2022.2126313","url":null,"abstract":"ABSTRACT The wind turbine blade trailing edge (TE) is frequently exposed to compressive loading and can even be damaged under complex operating conditions. Among the most typical TE failure modes is the adhesive-joint failure, so it is necessary to evaluate the structural behavior of the adhesive joints in TE under compressive loading. In this regard, an improved testing method was proposed for blade subcomponents. Specifically, the experiment was performed on a composite TE structural specimen under compressive loading to reveal its internal failure mechanism. The results showed that when the TE specimen was compressed under increasing load, buckling deformation occurred gradually at the sandwich laminates. Also, the bending deformations of the laminates on the suction and pressure sides were different in the bonding region. The resultant shearing effect led to the structural adhesive undergoing brittle fracture, which then triggered debonding and extension, finally causing the debonding failure of the trailing-edge specimen. To guarantee the safety of a blade under edge-wise loading, it is suggested that the structural strength of the TE should be emphasized during the blade design process.","PeriodicalId":14778,"journal":{"name":"Journal of Adhesion","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48702028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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