Journal of Materials Science-Materials in Medicine
The objective of this study was to compare the benefits of titanium 2448 (Ti2448) half-pin and titanium-6 aluminium-4 vanadium (TAV) half-pin on reducing pin loosening during external fracture fixation. Although having similar strength, Ti2448 half-pin had even lower elastic modules(33 GPa) when compared with TAV half-pin (110 GPa), which was similar to that of cortical bone (20 GPa). In the external fixation of tibial model fractures and canine cadaveric tibia fractures, Ti2448 half-pin had greater recoverable deformation and less stress concentration at the pin-bone interface in compression, torsion, and four-points bending test. Then, tibial fractures were created in 24 dogs and stabilized with four half-pins of either Ti2448 or TAV in each animal. At 4 and 8 weeks post-operatively, fracture healing and pin loosening was assessed by radiographic grading scale. The scores of Ti2448 group were significantly higher than those of TAV group. Micro-CT analysis also indicated larger quantity and higher quality of newly formed bone at pin-bone interface in Ti2448 group. Histology observation showed the newly formed bone integrated well into the threads of Ti2448 half-pins. In contrast, there was a layer of necrotic tissue between the bone tissue and TAV half-pin at pin-bone interface in TAV group. The extraction torque values of Ti2448 half-pins near the fracture line were significantly higher than those TAV pins. In conclusion, the Ti2448 half-pin with low elastic modulus could enhance osseointegration and reduce pin loosening when compared with TAV half-pin. It is a promising biomaterial for constructing external fixation system in clinical application.
关键词:
skeletal fixation;stainless-steel;tract infection;schanz screws;bone;complications;strength;fractures;interface;movement
王晓旭
,
陈利
材料工程
doi:10.3969/j.issn.1001-4381.2011.11.001
通过单根Z-pin从复合材料层合板中拔出的试验方法,测试了Z-pin的拔出强度,计算了Z-pin的临界埋入深度,并引入抗拉强度利用率概念来表征Z-pin的抗拉强度在拔出过程中的利用程度.结果表明,直径0.50mm和0.28mm的Z-pin临界埋入深度分别约为5.1mm和3.1mm.当Z-pin的埋入深度小于临界埋入深度时,Z-pin从层板中拔出；Z-pin拔出强度与埋入深度成正比,与Z-pin的直径成反比；当Z-pin的埋入深度大于临界埋入深度时,Z-pin发生断裂,Z-pin的抗拉强度利用率达到100％.最后提出了提高抗拉强度利用率的建议.
关键词:
Z-pin
,
拔出强度
,
复合材料
,
拔出试验
,
抗拉强度
王晓旭
,
陈利
航空材料学报
doi:10.3969/j.issn.1005-5053.2011.4.017
通过三种复合材料Z-pin的轴向压缩试验,观察了各Z-pin的压缩行为,分析了三种复合材料Z-pin在不同长度时的极限应力及其失效形式.结果表明,直径为0.50mm的碳纤维Z-pin的压缩性能最好,其各长度Z-pin所能承担的极限应力都较大.直径0.28mm的碳纤维Z-pin易发生失稳现象,芳纶纤维Z-pin在压缩力的作用下,接触端容易受到破坏.两种碳纤维Z-pin临界应力的理论值与试验值吻合较好,但芳纶纤维Z-pin的临界应力的试验值比理论值偏低.
关键词:
Z-pin
,
复合材料
,
压缩试验
,
临界应力
郑锡涛
,
李泽江
,
杨帆
复合材料学报
针对Z-pin增强复合材料层合板,开展了断裂韧性的试验研究.研究选取了3种Z-pin直径(0.28、0.52、0.80 mm)且每种直径下分别以3种分布形式(5×5、8×8、10×10)排布Z-pin的增强方式,为了确定比较基准,试验中同时测试了不含Z-pin的复合材料层合板试样.通过Z-pin拔出试验测试了3种直径Z-pin从基体拔出过程中的载荷-位移关系.利用双悬臂梁试验和端部开口弯曲试验分别测试了不含Z-pin和含Z-pin试样的Ⅰ型断裂应变能释放率GIC、Ⅱ型断裂应变能释放率GⅡC.试验结果表明:与不含Z-pin的结构相比,Z-pin增强试样的Ⅰ型断裂应变能释放率GIC增大了83%～1110%,Ⅱ型断裂应变能释放率GⅡC增大了23%～438%;在相同Z-pin体积含量下,与增大Z-pin直径相比,增大Z-pin分布密度能更有效地提高复合材料层合板的断裂韧性.
关键词:
Z-pin增强
,
Ⅰ型断裂
,
Ⅱ型断裂
,
应变能释放率
,
断裂韧性
董晓阳
,
李勇
,
李吻
,
张向阳
,
肖军
材料工程
doi:10.11868/j.issn.1001-4381.2015.02.005
为了研究Z-pin对单搭接头弯曲性能的影响,制备了不同参数Z-pin增强单搭接头试样,研究了Z-pin单搭接头在三点弯曲载荷下连接性能.结果表明:Z-pin(直径0.5mm)体积分数从0％～1.5％时,弯曲载荷随Z-pin体积分数的增加而增加,体积分数在1.5％～3.0％范围内时,试样的弯曲载荷随Z-pin体积分数的增加而下降,Z-pin体积分数为1.5％时达到最大值1303.2N;Z-pin直径为0.3～0.7mm时(体积分数1.5％),峰值载荷随着直径的增加而增加,0.7mm增强接头的弯曲载荷比0.3mm增强接头高出27.9％.Z-pin植入角度对单搭接头弯曲性能影响不大.另外,随着搭接长度的增加,单搭接头的弯曲性能提高.
关键词:
复合材料
,
Z-pin增强
,
单搭接头
,
弯曲
刘(韦华)
,
矫桂琼
材料科学与工程学报
碳纤维平纹编织物和碳纤维Z-pin制备的预成型体,通过化学气相渗透(CVI)工艺制成Z-pin增强平纹编织陶瓷基复合材料层压板.通过双悬臂梁试验研究Z-pin增强平纹编织陶瓷基复合材料层压板的层间Ⅰ型应变能释放率和增强机理.研究Z-pin面积密度对层间Ⅰ型应变能释放率的影响.结果表明:Z-pin增强平纹编织陶瓷基复合材料层压板主要增强机理表现为层间裂纹扩展受阻,Z-pin与层压板界面解离,Z-pin桥联裂纹和Z-pin拔出;增大Z-pin面积密度,层间Ⅰ型应变能释放率增大.
关键词:
陶瓷基复合材料
,
应变能释放率
,
双悬臂梁
,
Z-pin
李志怀
,
夏冠群
,
程宗权
,
黄文奎
,
伍滨和
功能材料与器件学报
doi:10.3969/j.issn.1007-4252.2003.01.008
研究了 PIN结构 GaInAsSb 红外探测器的暗电流特性,建立了器件的 PSPICE模型.模拟结果 与实际测试结果基本符合.计算结果表明,器件表面和内部的缺馅及表面复合电流对器件的反向 特性起主要作用 ,当反向偏压大于 0.35V,缺陷引起的隧穿电流对器件暗电流起主要作用.
关键词:
GaInAsSb
,
红外探测器
,
PSPICE
杜龙
,
矫桂琼
,
黄涛
,
李朝光
材料科学与工艺
通过试验研究了Z-pin增强泡沫夹层结构的弯曲性能,与未增强材料进行比较.提出采用树脂Z-pin对泡沫夹层结构进行横向增强,比较了碳pin和树脂pin的不同增强效果.结果表明,横向增强能够极大地改善泡沫夹层结构的弯曲性能,树脂pin的增强作用虽然弱于碳pin,但同样具有明显的增强效果.在此基础上,基于Z-pin增强泡沫夹芯的力学性能,对夹层结构的弯曲刚度和弯曲最大破坏载荷进行预测.最后考察了增强Z-pin各参数对泡沫夹层结构自振频率的影响,为其在航空航天等振动结构中通过合理的阻尼设计达到调频的目的打下基础.
关键词:
夹层复合材料
,
Z-pin增强
,
力学性能
