We determined the effects of adhesive type and loose tenon dimensions （length and thickness） on bending strength of T-shaped mor- tise and loose-tenon joints. Polyvinyl acetate （PVAc） and two-component polyuretha...We determined the effects of adhesive type and loose tenon dimensions （length and thickness） on bending strength of T-shaped mor- tise and loose-tenon joints. Polyvinyl acetate （PVAc） and two-component polyurethane （PU） adhesives were used to construct joint specimens. The bending moment capacity of joints increased significantly with increased length and thickness of the loose tenon. Bending moment capacity of joints constructed with PU adhesive was approximately 13% higher than for joints constructed with PVAc adhesive. We developed a predictive equation as a function of adhesive type and loose tenon dimensions to estimate the strength of the joints constructed of oriental beech （Fagus orientalis L.） under uniaxial bending load.展开更多
We studied the effect of loose tenon dimensions on stress and strain distributions in T-shaped mortise and loose tenon （M＆amp;LT） furni-ture joints under uniaxial bending loads, and determined the effects of loose ...We studied the effect of loose tenon dimensions on stress and strain distributions in T-shaped mortise and loose tenon （M＆amp;LT） furni-ture joints under uniaxial bending loads, and determined the effects of loose tenon length （30, 45, 60, and 90 mm） and loose tenon thickness （6 and 8 mm） on bending moment capacity of M＆amp;LT joints constructed with polyvinyl acetate （PVAc） adhesive. Stress and strain distributions in joint elements were then estimated for each joint using ANSYS finite element （FE） software. The bending moment capacity of joints increased significantly with thickness and length of the tenon. Based on the FE analysis results, under uniaxial bending, the highest shear stress values were obtained in the middle parts of the tenon, while the highest shear elastic strain values were estimated in glue lines between the tenon sur-faces and walls of the mortise. Shear stress and shear elastic strain values in joint elements generally increased with tenon dimensions and corre-sponding bending moment capacities. There was consistency between predicted maximum shear stress values and failure modes of the joints.展开更多
Based on the theory of reliability-based structural shape optimization, exact expressions of the sensibility using the stochastic finite element method for contact problems were derived in detail, and the basic steps ...Based on the theory of reliability-based structural shape optimization, exact expressions of the sensibility using the stochastic finite element method for contact problems were derived in detail, and the basic steps of structural optimization were given. A coattail-type tenon/mortise of an aero-engine was optimized. In this model, the maximum equivalent stress of the nodes on the boundary of the tenon was the objective function; the width of tooth’s neck and the side surface’s slope angle of a tenon were design variables, with constraints of tension stress, extrusion stress and reliability index. The result showed that the distributions of the contact pressure between tenon and mortise, the equivalence stress and reliability index were more reasonable. It validates the correctness of the optimization model and the reliability-based structural shape optimization, and provides valuable references for structural design of the tenon/mortise.展开更多
<b><span>Background:</span></b><span> Corona Mortis is an abnormal blood vessels connecti</span><span>ng</span><span> Between obturator and external iliac systems ...<b><span>Background:</span></b><span> Corona Mortis is an abnormal blood vessels connecti</span><span>ng</span><span> Between obturator and external iliac systems of vessels and inferior epigastric vessels. It is located behind the superior public ramus at a variable distance from the symphysis pubis. Orthopaedic surgeons and obestitrtion found these vessels in the field of surgery. So displaced fractures or iatrogenic injury, can cause life threatening bleeding and hence these vascular anomalies are referred to us crown of death. The bulk of the studies about the corona mortise were conducted in the cadavers or </span><b><span>3D</span></b><span> </span><b><span>CT</span></b><span> angiography and there</span><span> was</span><span> no studies were conducted about corona mortise in Sudan. The purpose of this study was to study the corona mortis anatomical and clinical implication in the anterior approaches to the pelvis and acetabulum in Sudanese patient. </span><b><span>Methodology:</span></b><span> Hospital based descriptive cross-sectional study was conducted among patients sustaining anterior pelvic anterior acetabulum fracture and underwent open reduct</span><span>i</span><span>on internal fixation by reconstruction plates. This study was conducted in Bahri Teaching Hospital from June 2017 to June 2018. Through the most common anterior approaches to the pelvis and acetabulum (Stoppa-modified stoppa-ilioinguinal), done by single surgeon and fulfil data sheet intra</span><span>-</span><span>operatively.</span><span> </span><b><span>Results:</span></b><span> In a total of 30 pelvic halves coro</span><span>na mortis was detected in 13 patients (43%).The Majority in the</span><span> Rt.hemipelvies 7</span><span> </span><span>(53.8%) specimens: arterial 4</span><span>/</span><span>13 (30.8%), venous 1</span><span>/</span><span>13 (7.7%) and both arterial and venous in 8</span><span>/</span><span>13 (61.5%) specimens respectively.</span><span> </span><span>Of these (53.9%) had a large Diameter ></span><span> </span><span>5</span><span> </span><span>mm and the largest one measure 80</span><span> </span><span>mm, with mean distance From the symphysis 5.8</span><span> </span><span>+</span><span> </span><span>1.6</span><span> </span><span>mm.</span><span> </span><b><span>Conclusion:</span></b><span> Only 13 patients have corona mortis, 12 of them were arterial with diameter more than 5</span><span> </span><span>mm</span><span> </span><span>(53%), and thus surgeon should exercise caution during Surgery and secure its site to help minimizing surgery time, Clear surgical field and prevent iatrgenic injury.</span>展开更多
文摘We determined the effects of adhesive type and loose tenon dimensions （length and thickness） on bending strength of T-shaped mor- tise and loose-tenon joints. Polyvinyl acetate （PVAc） and two-component polyurethane （PU） adhesives were used to construct joint specimens. The bending moment capacity of joints increased significantly with increased length and thickness of the loose tenon. Bending moment capacity of joints constructed with PU adhesive was approximately 13% higher than for joints constructed with PVAc adhesive. We developed a predictive equation as a function of adhesive type and loose tenon dimensions to estimate the strength of the joints constructed of oriental beech （Fagus orientalis L.） under uniaxial bending load.
文摘We studied the effect of loose tenon dimensions on stress and strain distributions in T-shaped mortise and loose tenon （M＆amp;LT） furni-ture joints under uniaxial bending loads, and determined the effects of loose tenon length （30, 45, 60, and 90 mm） and loose tenon thickness （6 and 8 mm） on bending moment capacity of M＆amp;LT joints constructed with polyvinyl acetate （PVAc） adhesive. Stress and strain distributions in joint elements were then estimated for each joint using ANSYS finite element （FE） software. The bending moment capacity of joints increased significantly with thickness and length of the tenon. Based on the FE analysis results, under uniaxial bending, the highest shear stress values were obtained in the middle parts of the tenon, while the highest shear elastic strain values were estimated in glue lines between the tenon sur-faces and walls of the mortise. Shear stress and shear elastic strain values in joint elements generally increased with tenon dimensions and corre-sponding bending moment capacities. There was consistency between predicted maximum shear stress values and failure modes of the joints.
基金National Natural Science Foundation of China (5 9875 0 3 7)
文摘Based on the theory of reliability-based structural shape optimization, exact expressions of the sensibility using the stochastic finite element method for contact problems were derived in detail, and the basic steps of structural optimization were given. A coattail-type tenon/mortise of an aero-engine was optimized. In this model, the maximum equivalent stress of the nodes on the boundary of the tenon was the objective function; the width of tooth’s neck and the side surface’s slope angle of a tenon were design variables, with constraints of tension stress, extrusion stress and reliability index. The result showed that the distributions of the contact pressure between tenon and mortise, the equivalence stress and reliability index were more reasonable. It validates the correctness of the optimization model and the reliability-based structural shape optimization, and provides valuable references for structural design of the tenon/mortise.
文摘<b><span>Background:</span></b><span> Corona Mortis is an abnormal blood vessels connecti</span><span>ng</span><span> Between obturator and external iliac systems of vessels and inferior epigastric vessels. It is located behind the superior public ramus at a variable distance from the symphysis pubis. Orthopaedic surgeons and obestitrtion found these vessels in the field of surgery. So displaced fractures or iatrogenic injury, can cause life threatening bleeding and hence these vascular anomalies are referred to us crown of death. The bulk of the studies about the corona mortise were conducted in the cadavers or </span><b><span>3D</span></b><span> </span><b><span>CT</span></b><span> angiography and there</span><span> was</span><span> no studies were conducted about corona mortise in Sudan. The purpose of this study was to study the corona mortis anatomical and clinical implication in the anterior approaches to the pelvis and acetabulum in Sudanese patient. </span><b><span>Methodology:</span></b><span> Hospital based descriptive cross-sectional study was conducted among patients sustaining anterior pelvic anterior acetabulum fracture and underwent open reduct</span><span>i</span><span>on internal fixation by reconstruction plates. This study was conducted in Bahri Teaching Hospital from June 2017 to June 2018. Through the most common anterior approaches to the pelvis and acetabulum (Stoppa-modified stoppa-ilioinguinal), done by single surgeon and fulfil data sheet intra</span><span>-</span><span>operatively.</span><span> </span><b><span>Results:</span></b><span> In a total of 30 pelvic halves coro</span><span>na mortis was detected in 13 patients (43%).The Majority in the</span><span> Rt.hemipelvies 7</span><span> </span><span>(53.8%) specimens: arterial 4</span><span>/</span><span>13 (30.8%), venous 1</span><span>/</span><span>13 (7.7%) and both arterial and venous in 8</span><span>/</span><span>13 (61.5%) specimens respectively.</span><span> </span><span>Of these (53.9%) had a large Diameter ></span><span> </span><span>5</span><span> </span><span>mm and the largest one measure 80</span><span> </span><span>mm, with mean distance From the symphysis 5.8</span><span> </span><span>+</span><span> </span><span>1.6</span><span> </span><span>mm.</span><span> </span><b><span>Conclusion:</span></b><span> Only 13 patients have corona mortis, 12 of them were arterial with diameter more than 5</span><span> </span><span>mm</span><span> </span><span>(53%), and thus surgeon should exercise caution during Surgery and secure its site to help minimizing surgery time, Clear surgical field and prevent iatrgenic injury.</span>
