Current and future structural applications for composite laminates frequently involve design solutions combining composite laminates and metal; the materials must be joined. Two conventional means of joining are avail...Current and future structural applications for composite laminates frequently involve design solutions combining composite laminates and metal; the materials must be joined. Two conventional means of joining are available mechanical joining and adhesive bonding. Both methods have critical disadvantages. A novel surface treatment for metals developed at TWI, Surfi-Sculpt, leads to the formation of surface protrusions on metal surfaces. These protrusions are typically 1.0 mm high and 0.6 mm in diameter. The surface modified metal can be bonded with composite laminates to form a Comeld～TM joint. These joints can be described as a combination of mechanical fastening and adhesive bonding. This paper describes our current work using finite element modelling to optimize the protrusions in respect to their geometry and distribution. The simulations require multi-scale modelling techniques to transfer results between the global model of the whole joint and the unit cell models containing a protrusion. Results from the simulations show critical effects on stress distributions arising from changing protrusion geometry. These joints show significant advantages over conventional adhesive joining technologies and their application would allow improved performance for combinations of metal and composite laminates.展开更多
目的探讨Single bond^(?)Universal等3种不同类型自酸蚀粘接剂与牙本质的粘接强度和耐久性。方法选取2016年5—7月解放军总医院口腔颌面外科拔除的24颗新鲜人离体第三磨牙,随机分为3组,每组8颗,分别选用Clearfil SE Bond(SE组)、G-Bond ...目的探讨Single bond^(?)Universal等3种不同类型自酸蚀粘接剂与牙本质的粘接强度和耐久性。方法选取2016年5—7月解放军总医院口腔颌面外科拔除的24颗新鲜人离体第三磨牙,随机分为3组,每组8颗,分别选用Clearfil SE Bond(SE组)、G-Bond plus(GBp组)、Single bond^(?)Universal(SBU组)等3种自酸蚀粘接剂与新鲜牙本质粘接并制备试件。每组挑选出完整试件160个,再分为两个亚组(各80个试件),分别在即刻与人工唾液浸泡6个月后行微拉伸粘接强度实验,体视显微镜下观察试件断裂类型。结果 SE组、GBp组、SBU组即刻牙本质粘接强度分别为(55.70±11.07)、(52.85±7.54)和(62.82±8.70)MPa,其中SBU组高于SE组和GBp组,差异有统计学意义(P<0.05)。人工唾液保存6个月后,SE组、GBp组、SBU组牙本质粘接强度分别为(13.51±4.99)、(43.53±6.82)和(49.13±6.58)MPa,3组之间差异均有统计学意义(P<0.05)。6个月时粘接界面观察,SE组断裂模式均为粘接界面断裂;GBp组16个试件为牙本质内聚断裂,4个试件为复合树脂内聚断裂;SBU组28个试件为牙本质内聚断裂,8个试件为复合树脂内聚断裂。结论 Single bond?Universal即刻牙本质粘接强度和人工唾液老化后6个月粘接强度均显著高于Clearfil SE Bond、G-Bond plus;Single bond^(?)Universal粘接强度大,稳定耐久,可提供良好的粘接效果。展开更多
基金Supported by TWI, UK We gratefully acknowledge the financial support and the provision of specimens .
文摘Current and future structural applications for composite laminates frequently involve design solutions combining composite laminates and metal; the materials must be joined. Two conventional means of joining are available mechanical joining and adhesive bonding. Both methods have critical disadvantages. A novel surface treatment for metals developed at TWI, Surfi-Sculpt, leads to the formation of surface protrusions on metal surfaces. These protrusions are typically 1.0 mm high and 0.6 mm in diameter. The surface modified metal can be bonded with composite laminates to form a Comeld～TM joint. These joints can be described as a combination of mechanical fastening and adhesive bonding. This paper describes our current work using finite element modelling to optimize the protrusions in respect to their geometry and distribution. The simulations require multi-scale modelling techniques to transfer results between the global model of the whole joint and the unit cell models containing a protrusion. Results from the simulations show critical effects on stress distributions arising from changing protrusion geometry. These joints show significant advantages over conventional adhesive joining technologies and their application would allow improved performance for combinations of metal and composite laminates.
文摘目的探讨Single bond^(?)Universal等3种不同类型自酸蚀粘接剂与牙本质的粘接强度和耐久性。方法选取2016年5—7月解放军总医院口腔颌面外科拔除的24颗新鲜人离体第三磨牙,随机分为3组,每组8颗,分别选用Clearfil SE Bond(SE组)、G-Bond plus(GBp组)、Single bond^(?)Universal(SBU组)等3种自酸蚀粘接剂与新鲜牙本质粘接并制备试件。每组挑选出完整试件160个,再分为两个亚组(各80个试件),分别在即刻与人工唾液浸泡6个月后行微拉伸粘接强度实验,体视显微镜下观察试件断裂类型。结果 SE组、GBp组、SBU组即刻牙本质粘接强度分别为(55.70±11.07)、(52.85±7.54)和(62.82±8.70)MPa,其中SBU组高于SE组和GBp组,差异有统计学意义(P<0.05)。人工唾液保存6个月后,SE组、GBp组、SBU组牙本质粘接强度分别为(13.51±4.99)、(43.53±6.82)和(49.13±6.58)MPa,3组之间差异均有统计学意义(P<0.05)。6个月时粘接界面观察,SE组断裂模式均为粘接界面断裂;GBp组16个试件为牙本质内聚断裂,4个试件为复合树脂内聚断裂;SBU组28个试件为牙本质内聚断裂,8个试件为复合树脂内聚断裂。结论 Single bond?Universal即刻牙本质粘接强度和人工唾液老化后6个月粘接强度均显著高于Clearfil SE Bond、G-Bond plus;Single bond^(?)Universal粘接强度大,稳定耐久,可提供良好的粘接效果。
