Clinical Effectiveness of the Plate Screw Internal Fixation Technique in the Treatment of Patients with Traumatic Fractures of Long Bones in the Lower Extremities

Objective: To investigate the effectiveness of the plate screw internal fixation technique on the clinical outcomes of patients with traumatic fractures of long bones in the lower extremities. Methods: From January 2022 to December 2023, 70 patients with traumatic fractures of long bones in the lower extremities were admitted to the hospital and randomly divided into two groups: the control group and the observation group, each consisting of 35 cases. The control group underwent traditional closed interlocking intramedullary nailing, while the observation group received internal fixation with steel plates and screws. Relevant surgical indicators, treatment effectiveness, and postoperative complication rates were compared between the two groups. Results: The observation group exhibited significantly short surgical duration (80.65 ± 5.01 vs. 88.36 ± 5.26 minutes), fracture healing time (13.27 ± 0.32 vs. 15.52 ± 0.48 weeks), and hospitalization days (10.49 ± 1.13 vs. 16.57 ± 1.15 days) compared to the control group (P = 0.000). The effective treatment rate was significantly higher in the observation group (29/82.86%) than in the control group (21/60.00%), with a significant difference observed (χ2 = 4.480, P = 0.034). Additionally, the complication rate in the observation group (2/5.71%) was significantly lower than that in the control group (8/22.86%), with a correlated difference (χ2 = 4.200, P = 0.040). Conclusion: The plate screw internal fixation technique demonstrates significant clinical efficacy in treating traumatic fractures of long bones in the lower extremities. It improves the healing rate, reduces complications, and represents a safe and effective treatment strategy worthy of widespread use and application.

Fixation of Calcaneal Tuberosity Beavis II Fracture in Elderly Patients Using Locking Plate Combined with Tension Screw

Background:Calcaneus is the largest bone of foot and the main load-bearing structure of heel.The incidence of simple calcaneal tubercle avulsion fracture is low,accounting for about 1%to 3%of all calcaneal fractures.Beavis II fracture has large bone fracture,obvious displacement,obvious soft tissue irritation,and often leads to skin necrosis.It needs surgical treatment,reduction and fixation as soon as possible.Although open reduction and tension screw internal fixation is used for Beavis II calcaneal tubercle fracture,but the failure rate is more common.Methods:This study retrospectively analyzed the surgical treatment of calcaneal tubercle Beavis II fracture over 55 years old in our hospital from January 2013 to January 2019.The patients were treated with tension screw combined with locking plate,and followed up and analyzed.Results:12 patients in this group were followed up for 12 to 36 months(mean 20 months).After operation,the fracture healed smoothly in all patients,the healing time was 8 to 12 weeks(mean 10.7 weeks),and there were no complications such as poor incision healing,fracture displacement,internal fixation loosening,fracture and so on.When the patients were followed up 18 weeks after operation,the AOFAS score was 47 to 100,with an average of 91.1,of which 8 cases were excellent,3 good and 1 poor,with an excellent and good rate of 91.7%.Conclusion:Our hospital has been treated with tension screw combined with locking plate,fixed firmly,can early functional exercise,achieved good results.

Comparison of Efficacy between 3D Navigation-Assisted Percutaneous Iliosacral Screw and Minimally Invasive Reconstruction Plate in Treating Sacroiliac Complex Injury

The clinical efficacy was compared between 3D navigation-assisted percutaneous iliosacral screw(3DPS)and minimally invasive reconstruction plate(MIRP)in treating sacroiliac complex injury and the surgical procedures of 3DPS were introduced.A retrospective analysis was performed on 49 patients with sacroiliac complex injury from March 2013 to May 2017.Twenty-one cases were treated by 3DPS,and 28 cases by MIRP.Intraoperative indexes as operative time,blood loss,incision length,length of hospital stay and postoperative complications were respectively documented.Quality of reduction was postoperatively evaluated by Matta radiological criteria,and clinical effect was assessed by Majeed scoring criteria at the last followup.Operative time and hospital stay were significantly shortened,and blood loss,and incision length were significantly reduced in 3DPS group as compared with those in MIRP group(P<0.05).No statistically significant difference was found between 3DPS group and MIRP group in the assessment of reduction and function(P>0.05).It was concluded that both 3DPS and MIRP can effectively treat the sacroiliac complex injury,and 3DPS can provide an accurate,safe and minimally invasive fixation with shorter operative time and hospital stay.

Screw placement is everything: Risk factors for loss of reduction with volar locking distal radius plates

AIM To determine factors correlated with postoperative radial shortening in patients with distal radius fractures treated with volar locking distal radius plates.METHODS A total of 250 patients with a distal radius fracture stabilised with volar locking plates between January 2010 and December 2014 were included in a multicentre retrospective cohort study. We measured the distance of the distal locking screws to the joint line immediately postoperatively and then measured radial shortening after six to eight weeks using the change in ulnar variance.RESULTS Multivariate linear regression analysis showed that there was a significant linear association between the distance of the screws from the joint line and radial shortening. No other patient, injury, or treatment-related characteristic significantly influenced radial shortening in multivariate analysis.CONCLUSION Distal locking screws should be placed as close as possible to the subchondral joint line to prevent postoperative loss of reduction.

SEM observation of bone interface of titanium-coated 317L plate screw

The scanning electron microscope (SEM) results of bone interface of titanium-coated 317L plate screw are reported in this article. 317L plate screw had a rough surface composed of sprayed pure titanium which formed a bone/metal interface in biointegration after implanted into the mandible of dog. Though a bone/metal interface in osseointegration was also formed on the surface of uncoated 317L plate screw after implantation, a smal1 space was seen between the bone and surface of the screw, indicating that the tissue compatibility of titanium-coated 317L plate screw may be better than that of the non-coated screw.

Neutralization versus Compression Plate on Lateral Malleolus Fracture:Is Lag Screw Necessary?

Introduction: Our aim was to compare clinical and radiological results of lateral malleolus fracture treated with neutralization and compression plate. Material and Methods: 54 patients with isolated lateral malleolus fractures treated between March 2012 and April 2015 at Fatih Sultan Mehmet Training and Research Hospital were evaluated with the Ankle-Hindfoot Scale of the American Orthopedic Foot and Ankle Society (AOFAS) score (excellent, ≥90;good, 75 - 89;acceptable, 50 - 74;poor, Results: There was no significant change in AOFAS, VAS, PSS and the union rates between two plating techniques. Conclusion: Similar results have shown both of two plating techniques were successful treating isolated lateral malleolus fracture.

The Effects of Bone Screw Configurations on the Interfragmentary Movement in a Long Bone Fixed by a Limited Contact Locking Compression Plate

The locking compression plates (LCP) are efficient tools in open reduction and internal fixation (ORIF), especially in osteoporotic bones. Two important factors of screw density and screw position can affect the functionality of the bone plate. Several studies have assessed the influence of the screw configurations on the bone-plate stiffness, but the effects of screw positions on the interfragmentary strain, εIF of LCP construct have not been investigated yet. In this study, finite element method was used to investigate the influence of screws number and position on the interfragmentary strain of LCP-femur system for a mid-shaft fracture. Results of this study showed that by insertion of screws closer to the fracture site, εIF decreases by 2nd degree polynomial function versus screw position, but by adding the screws from the ends of the plate, or by moving and placing the screws towards the fracture site, the reduction of εIF will be linear. Results of this study were compared and are in agreement with some studies in the literature, even though their scope was mostly stability of the bone-implant system, whereas our scope was focused on the interfragmentary strain.

Distal clavicle fractures treated by anteroinferior plating with a single screw: Two case reports

BACKGROUND For the treatment of distal clavicle fractures,each treatment method has its own advantages and disadvantages,and there is no optimal surgical solution.CASE SUMMARY Based on this,we report 2 cases of distal clavicle fractures treated utilizing an anterior inferior plate with a single screw placed in the distal,in anticipation of providing a better surgical approach to distal clavicle fracture treatment.Two patients were admitted to the hospital after trauma with a diagnosis of distal clavicle fracture,and were admitted to the hospital for internal fixation of clavicle fracture by incision and reduction,with good postoperative functional recovery.CONCLUSION With solid postoperative fixation and satisfactory prognostic functional recovery,this technique has been shown to be simple,easy to perform and effective.

Comparison of lag screws and double Y-shaped miniplates in the fixation of anterior mandibular fractures

BACKGROUNDMandibular fractures constitute about 80.79% of maxillofacial injuries inAlexandria University, either as isolated mandibular fractures or as a part ofpanfacial fractures. The combination of symphyseal and parasymphyseal fracturesrepresent 47.09% of the total mandibular fractures.AIMTo compare the effectiveness of lag screws vs double Y-shaped miniplates in thefixation of anterior mandibular fractures.METHODSThis study is a prospective randomized controlled clinical trial, performed onsixteen patients with anterior mandibular fractures. Patients were divided equallyinto two groups, each consisting of eight patients. Group 1: Underwent openreduction and internal fixation using two lag screws. Group 2: Underwent openreduction and internal fixation using double Y-shaped plates. The followingparameters were assessed: operating time in minutes, pain using a visual analogscale, edema, surgical wound healing for signs and symptoms of infection,occlusion status and stability, maximal mouth opening, and sensory nervefunction. Cone beam computed tomography was performed at 3 and 6 mo tomeasure bone density and assess the progression of fracture healing.RESULTSThe study included 13 males (81.3%) and 3 females (18.8%) aged 26 to 45 years(mean age was 35.69 ± 6.01 years). The cause of trauma was road traffic accidentsin 10 patients (62.5%), interpersonal violence in 3 patients (18.8%) and othercauses in 3 patients (18.8%). The fractures comprised 10 parasymphyseal fractures(62.5%) and 6 symphyseal fractures (37.5%). The values of all parameters were comparable in both groups with no statistically significant difference except forthe mean bone density at 3 mo postoperatively which was 946.38 ± 66.29 in group 1 and 830.36 ± 95.53 in group 2 (P = 0.015).CONCLUSIONBoth lag screws and double Y-shaped miniplates provide favorable means offixation for mandibular fractures in the anterior region. Fractures fixed with lagscrews show greater mean bone density at 3 mo post-operation, indicative ofhigher primary stability and faster early bone healing. Further studies with largersample sizes are required to verify these conclusions.

锁定钢板联合皮质螺钉内固定治疗踝关节骨折伴下胫腓分离对踝关节功能及生活质量的影响

目的 探讨锁定钢板联合皮质螺钉内固定治疗踝关节骨折伴下胫腓分离对踝关节功能及生活质量的影响。方法 2020年5月~2021年12月我院收治的踝关节骨折伴下胫腓分离病人120例,依据随机数字表法将其分为对照组和观察组,每组各60例。对照组采用单纯皮质螺钉固定治疗,观察组采用锁定钢板联合皮质螺钉内固定治疗。术前、术后6个月对两组恢复功能对比,比较X线片、手术时间、愈合时间、术中失血量,术后并发症,生活能力(BI)评估两组病人生活能力。依照美国足踝外科协会评分系统评估病人踝关节功能。结果 术前两组病人关节功能无差异(P>0.05),术后,对照组最远行走评分(15.89±0.85)分、足部对线评分(15.06±0.71)分、疼痛反应评分(29.03±4.48)分、地面行走评分(15.65±0.59)分;观察组分别为(16.19±0.87)分、(15.29±0.76)分、(31.24±4.55)分、(15.96±0.68)分。观察组最远行走、足部对线、疼痛反应、地面步行高于对照组,差异有统计学意义(P<0.05)。与对照组比较,观察组术中出血量少,愈合时间较短,差异有统计学意义(P<0.05)。术前两组BI指数比较,差异无统计学意义(P>0.05);观察组术后BI指数高于对照组,两组比较,差异有统计学意义(P<0.05)。两组并发症总发生率比较无差异(P>0.05)。结论 锁定钢板联合皮质螺钉内固定技术治疗踝关节骨折合并下胫腓分离,可改善踝关节功能,降低术中出血量,促进愈合,提高生活能力。

两种内固定术式治疗高龄无移位型股骨颈骨折的疗效

目的比较股骨近端锁定接骨板与空心螺钉内固定治疗高龄无移位型股骨颈骨折的疗效。方法根据内固定不同将66例高龄无移位型股骨颈骨折患者分为接骨板组(32例,采用股骨近端锁定接骨板内固定治疗)和螺钉组(34例,采用空心螺钉内固定治疗)。记录两组手术情况、骨折愈合时间、髋关节Harris评分、术后并发症发生情况。结果患者均获得随访,时间6~95个月。手术时间、切口长度、术中出血量、术后血红蛋白下降量两组比较差异均无统计学意义(P>0.05),下床部分负重锻炼时间接骨板组早于螺钉组(P<0.05)。接骨板组骨折均顺利愈合,时间3.5~8.0(4.63±1.04)个月;螺钉组中出现1例骨折不愈合,其余33例骨折愈合时间为3.0~7.5(5.03±1.04)个月;骨折愈合时间两组比较差异无统计学意义(P>0.05)。术后6个月髋关节Harris评分两组比较差异无统计学意义(P>0.05);但髋关节Harris评分优良率接骨板组高于螺钉组(P<0.05)。术后早期并发症发生率两组比较差异无统计学意义(P>0.05),中远期并发症发生率螺钉组高于接骨板组(P<0.05)。结论股骨近端锁定接骨板与空心螺钉内固定治疗高龄无移位型股骨颈骨折均可获得满意疗效,与空心螺钉相比,股骨近端锁定接骨板治疗早期髋关节功能恢复更好,中远期并发症更少。

颈前路减压融合ROI-C^(TM)自锁系统治疗退行性颈椎病的Meta分析

目的:颈前路减压融合术是治疗退行性颈椎病的经典手术方式,钉板的使用增加了融合率及稳定性的同时,间接导致了邻近椎体退变和术后吞咽困难的发生。文章通过Meta分析方法比较ROI-C^(TM)自锁系统和传统融合器联合钉板内固定治疗退行性颈椎病患者的临床结果和并发症情况,为颈前路减压融合术中内固定方式的选择提供循证学支持。方法:检索中国知网、万方、维普、PubMed、Cochrane Library、Web of Science和Embase数据库,检索关于颈前路减压融合术中应用ROI-C^(TM)自锁系统与融合器联合钉板内固定治疗退行性颈椎病的中英文文献。检索时间范围为各数据库建库至2023年7月。由2名研究者严格按照纳入与排除标准选择文献,采用Cochrane偏倚风险工具对随机对照试验进行质量评价,NOS量表对队列研究进行质量评价。采用RevMan 5.4软件进行Meta分析。结局指标包括手术时间、术中出血量、日本骨科协会(Japanese Orthopaedic Association Scores,JOA)评分、颈椎功能障碍指数、C_(2)-C_(7)Cobb角、融合率、邻近椎体退变发生率、融合器沉降率和吞咽困难发生率。结果:共纳入13项研究,其中回顾性队列研究11项,随机对照试验2项,共1136例患者,ROI-C组569例,融合器联合钉板组567例。Meta分析结果显示:ROI-C组与融合器联合钉板组在手术时间(MD=-15.52,95%CI:-18.62至-12.42,P<0.00001),术中出血量(MD=-24.53,95%CI:-32.46至-16.61,P<0.00001),术后邻近节段退变率(RR=0.40,95%CI:0.27-0.60,P<0.00001)和术后总吞咽困难发生率(RR=0.18,95%CI:0.13-0.26,P<0.00001)均具有显著性差异。两者在术后JOA评分、颈椎功能障碍指数、C_(2)-C_(7)Cobb角、融合率和融合器沉降率方面无显著性差异(P≥0.05)。结论:在颈椎前路减压融合术中应用ROI-C^(TM)自锁系统与传统融合器联合钉板内固定治疗退行性颈椎病均可达到满意的临床效果,ROI-C^(TM)自锁系统操作更加简单,相比融合器联合钉板内固定能明显减少手术时间及术中出血量,在减少术后吞咽困难及邻近节段退变发生率等方面具有明显优势,对于跳跃型颈椎病及邻椎病翻修患者,更加推荐使用ROI-C^(TM)自锁系统。但鉴于其可能存在较高的沉降率,对于多节段且合并融合器沉降高危因素如骨质疏松、椎体终板破损的退行性颈椎病患者,仍建议使用融合器联合钉板内固定。

三维组架螺钉与环形钢板治疗Sanders ⅢAB型跟骨骨折的有限元分析

目的 探讨三维组架螺钉与环形钢板对SandersⅢAB型跟骨骨折的生物力学稳定性的影响。方法 收集1名26岁志愿者跟骨CT和MRI数据,建立SandersⅢAB型跟骨骨折的三维有限元模型,分别使用三维组架螺钉与环形钢板固定,施加700 N纵向载荷,比较不同模型骨块及内固定应力与位移变化情况。结果 在700 N纵向载荷下,两组模型骨块最大位移以及骨块与内固定最大应力均集中于后距关节面内固定与骨折线相交处。三维组架螺钉模型与环形钢板模型骨块整体位移相近。相较于环形钢板模型,三维组架螺钉模型骨块及内固定的最大应力和平均应力更小,位移与应力变化情况更接近完整跟骨模型。结论 SandersⅢAB型跟骨骨折固定时,三维组架螺钉与环形钢板两种固定方式均能提供良好稳定性。三维组架螺钉的生物力学性能优于环形钢板,更符合生物力学特点。

螺钉内固定与侧方支撑钢板内固定治疗LetenneurⅢ型Hoffa骨折的有限元分析

目的通过建立健康成年人膝关节三维模型,用有限元方法分析比较空心拉力螺钉(A模型)与侧方支撑钢板联合螺钉(B模型)在治疗LetenneurⅢ型Hoffa骨折的生物力学差异。方法采集健康成年人膝关节薄层CT图像,通过Mimics21.0软件提取初步模型、GeomagicWrap2021软件中对模型进一步进行光滑处理、Solidworks 2023软件中建立2种LetenneurⅢ型Hoffa骨折模型中所需内固定零件,并在Solidworks2023软件中将各零件进行拼装,模拟完成骨折内固定治疗、在Ansys2021软件中对模型进行网格划分,对膝关节模型进行有效性验证后,分别对两个内固定模型模拟施加人单腿站立载荷,计算2种模型的内固定Vonmises应力分布、骨折端及螺钉移位大小。比较2种模型的生物力学效应。结果①在对胫骨上端后方施加134N向前的力后,胫骨髁间嵴向前移位4.52mm,与前人结果相似。②A模型骨块最大移位为0.452mm,大于B模型骨块最大移位(0.357mm)。③A模型中内螺钉最大应力为73.3MPa,B模型中最大应力为119MPa,B模型中螺钉应力大小整体高于A模型;在A模型中,螺钉应力大小由远及近螺钉应力呈现降低的趋势;B模型中,螺钉应力大小由远及近呈“U”形。A模型中螺钉最大移位距离为0.52mm,B模型中螺钉最大移位距离为0.69mm,A、B模型中螺钉移位趋势均为由远及近螺钉移位逐渐增大,A、B两模型中螺钉移位大小相近。结论空心拉力螺钉结合侧方钢板在治疗LetenneurⅢⅡ型Hoffa骨折中具有更好的生物力学效果,更加利于患者术后康复.

三维组架螺钉与微创钢板固定SandersⅢ型跟骨骨折的有限元分析

背景:经皮复位加压固定的三维组架螺钉内固定在治疗SandersⅢ型跟骨骨折上已经取得了满意的临床疗效,但在生物力学方面是否可以达到微创钢板内固定的稳定性,以及对比之后的优势与缺点还不得而知。目的:通过有限元分析方法探讨不同内固定装置对SandersⅢ型跟骨骨折的固定效果。方法:选择1名26岁成年健康男性志愿者,根据其跟骨CT数据制作SandersⅢ型跟骨骨折有限元模型。选用经皮微创三维组架螺钉、跗骨窦微创钢板分别固定跟骨骨折模型,分别施加350,700N纵向载荷,分析2种模型的位移、应力分布情况,比较各种模型的稳定性。结果与结论:①三维组架螺钉模型中骨块与内植物的峰值应力明显低于微创钢板模型,三维组架螺钉模型中骨块与内植物的平均应力也明显低于微创钢板模型;②2种模型的最大位移均位于后距关节面内侧,三维组架螺钉模型的最大位移小于微创钢板模型;③微创钢板模型前突骨块与内侧骨块的纵向位移更小,三维组架螺钉模型内侧骨块与中段骨块的横向与垂直位移更小;④提示2种内固定模型均能提供满意的固定效果,其中三维组架螺钉模型使应力分布更均匀、骨块综合位移更小,能提供更好的横向与垂直稳定性,而微创钢板在维持纵向稳定性上更具优势。

一种移动式端面钻孔攻丝机的研制

自动化设备生产需要加工很多螺孔用于连接安装板,加工较长安装板的螺孔多选用立式加工中心垂直装夹,由于零件伸的太高造成装夹刚性太差;而采用卧式加工中心,设备昂贵成本太高。本文研制一款简易的端面钻孔攻丝装置,设计可移动式的工作台以降低设备占地空间,设计快速钻孔装置以提高钻孔攻丝的便捷性,增加一组工作台调节装置以扩大加工行程,改装一套攻丝系统以实现钻孔与自动攻丝功能,加装数显装置以提高孔坐标位置的精度,经过样机试制与切削实验,解决了较长安装板螺孔加工工艺问题,节约了生产成本。

两种内固定术治疗踝关节骨折的疗效比较

目的比较锁定钢板联合空心拉力螺钉与非锁定钢板联合普通螺钉内固定治疗踝关节骨折的疗效。方法将70例踝关节骨折患者根据治疗方法不同分为观察组(采用锁定钢板联合空心拉力螺钉内固定治疗,35例)和对照组(采用非锁定钢板联合普通螺钉内固定治疗,35例)。比较两组手术情况、骨折愈合情况、踝关节活动度、踝关节功能及并发症发生情况。结果患者均获得6个月随访。手术时间、住院时间、骨折愈合时间观察组均短(少)于对照组(P<0.05)。术中出血量、骨折愈合质量评分系统(RUSS评分)两组比较差异均无统计学意义(P>0.05)。术后3个月踝关节跖屈、背伸、内翻、外翻活动度观察组均大于对照组(P<0.05)。足部力线、地面步行、疼痛、最大步行距离评分:两组术后6个月均较术后3个月提高(P<0.05),术后3、6个月观察组均高于对照组(P<0.05)。并发症发生率观察组低于对照组(P<0.05)。结论与非锁定钢板联合普通螺钉相比,锁定钢板联合空心拉力螺钉内固定治疗踝关节骨折手术时间、住院时间、骨折愈合时间均较短,踝关节功能恢复较好,并发症较少。

带袢纽扣钢板与传统螺钉固定治疗Lisfranc韧带损伤的临床疗效观察

目的通过对比分析带袢纽扣钢板与传统螺钉固定治疗Lisfranc韧带损伤的临床疗效。方法回顾性分析46例涉及Lisfranc韧带损伤患者的临床资料,其中观察组23例,均接受带袢纽扣钢板固定治疗,对照组23例,均采用传统螺钉固定治疗。从一般资料、围术期参数、Lisfranc关节间距、疼痛、中足功能、术后1年AOFAS评分的优良率以及术后并发症发生率等方面进行对比分析,对其临床疗效进行综合评价。结果2组患者年龄、性别、BMI、受伤至手术时间、术中出血量比较差异无统计学意义(P>0.05)。观察组在术后6个月及1年时,疼痛更少,差异有统计学意义(P<0.05)。在术后1年时,观察组足功能表现更好,差异有统计学意义(P<0.05)。观察组共出现2例术后并发症(含切口浅表感染及腓深神经损伤各1例),对照组共9例出现术后并发症(1例切口浅表感染、2例螺钉断裂、3例Lisfranc关节再分离及3例创伤性关节炎),2组数据比较差异有统计学意义(P<0.05)。结论带袢纽扣钢板固定牢靠,术后患足功能恢复较好,并发症少。

钢板螺钉内固定技术治疗四肢骨折患者的效果及术后反应分析

目的探究钢板螺钉内固定技术治疗四肢骨折患者的临床效果及对术后并发症的影响。方法选取2019年5月—2023年8月江苏省连云港市赣榆区人民医院骨科接受手术治疗的80例四肢骨折患者为研究对象,采用信封法分为对照组和观察组,每组40例。对照组实施闭合复位交锁髓内钉固定治疗,观察组实施钢板螺钉内固定技术治疗。比较两组治疗有效性、临床指标、术后并发症发生情况。结果观察组治疗总有效率为95.00%,明显高于对照组的77.50%,差异有统计学意义(χ^(2)=5.165,P=0.023)。观察组手术、住院和骨折愈合时间均短于对照组,差异有统计学意义(P均<0.05);观察组术后并发症总发生率低于对照组,差异有统计学意义(P<0.05)。结论钢板螺钉内固定技术应用在四肢骨折患者治疗中安全有效,对患者尽早康复出院有利。

新型外包钢板-自攻螺钉连接胶合竹梁柱节点转动性能

针对胶合竹材不易预开槽和预开孔以及节点转动时竹材易发生横纹劈裂的问题,研究了新型外包钢板-自攻螺钉连接节点的转动性能。对T形外包钢板-自攻螺钉连接节点和双L形外包钢板-自攻螺钉连接节点共5个试件进行了单调加载试验,分析了节点的破坏模式、初始刚度、极限承载力、变形能力和延性系数。试验发现,T形外包钢板-自攻螺钉连接节点相较双L形外包钢板-自攻螺钉连接节点,各项受力性能参数均较优。布置直径小但数量多的自攻螺钉时,节点(T8×8-M)的破坏表现为钢板和自攻螺钉的受拉断裂以及与胶合竹柱连接的自攻螺钉受拉断裂,布置直径较大但数量少的自攻螺钉时,节点(T6×10-M)的破坏则表现为竹材的横纹劈裂和自攻螺钉的剪切破坏。横纹方向采用自攻螺丝加强,可改善节点的受力性能,对T形外包钢板-自攻螺钉连接节点改善更明显。现行《工程竹结构设计标准》(T/CECS 1101—2022)提供的节点设计方法偏于安全地预测胶合竹自攻螺钉连接梁柱节点的抗弯承载力。