This study investigates the wear degree of the shock absorber at the artificial knee joint due to bending degree of knee. As the stress distribution due to this angle is understood when the knee is bent, it can be shown how much and which configuration the wear of the shock absorber progresses in. On the basis of the analysis result, the stress applied at the shock absorber becomes higher and the equivalent stress becomes higher as the bending angle of knee is increased. The walking habit as the right attitude can be examined by applying the general joint as well as the artificial knee joint by using this study result

It has been more than twenty years since the application of GFRP bridge decks in construction fields. Recently, a few studies by governments and individual researchers have investigated in-use GFRP bridge decks. Areas of trouble include the problems of cracking, spalling and the de-bonding of the pavement or the wearing surface on GFRP bridge decks, all of which affect the long-term durability and serviceability of these new construction materials. Related to these problems, reflective cracks on asphalt pavement are directly related to pultruded GFRP bridge decks. This study investigates the behavior of an adhesive joint under weak-axis bending by tests and FE analyses to identify the causes of pavement cracks in in-use pultruded GFRP bridge decks. In detail, the flexural stiffness and the load-carrying capacities in strong and weak axes are measured during bending tests on pultruded GFRP decks. Next, tensile local failures of an epoxy adhesive due to the concentration of deformations at adhesive joints are identified via a weak-axis bending test. Finally, the tensile failure of an epoxy adhesive due to the local concentration of deformation at an adhesive joint under weak-axis bending is verified through a finite element analysis.

The purpose of this study was to identify the effects of manual facilitation and a stick on lumbar and hip joint flexion angles in subject with lumbar flexion syndrome during forward bending from a sitting position. Fifteen subjects with lumbar flexion syndrome were recruited for this study. As a pretest, all subjects performed three repetitions of bending the trunk forward until the tips of their fingers touched the target bar. After this pretest, the subjects practiced the forward bending of the trunk 10 times, using either manual facilitation or a stick. Then, as a posttest, all subjects repeated the pretest procedure. The flexion angles of lumbar spine and hip joint during forward bending in a sitting position were measured using a three-dimensional motion analysis system. A paired t-test was used to determine the statistical differences between pre-test and post-test flexion angles and pre- and post-test flexion angle differences between forward bending with manual facilitation and forward bending with a stick. The level of statistical significance was set at p=.05. The results of the study showed that the angle of the lumbar flexion decreased significantly and the bilateral hip flexion angle increased significantly when performing forward bending with stick and manual facilitation. Furthermore, the angle of lumbar flexion decreased significantly and the angle of bilateral hip flexion increased significantly in forward bending with a stick compared to forward bending with manual facilitation. The findings of this study indicate that both forward bending with manual facilitation and sticks could be used to prevent excessive lumbar flexion and increase hip flexion, and that forward bending with a stick is more effective than forward bending with manual facilitation for inducing lumbar spine and hip joint angle changes.

For the joint connection of the precast steel grid composite decks, the prefabricated joint which is composed of concrete shear key and high-tension bolts was already proposed. In this study, for the purpose of increasing the bending stiffness and bending strength of the proposed prefabricated joint section details of the proposed joint are modified, and through experimental tests the bending performance, such as stiffness and strength of a modified joint, is compared with those of the proposed joint. Test and analysis results show that the shear cracks in the concrete shear key are clearly reduced by the strengthening of the shear key using shear studs and additional rebars. According to analysis results of the moment-curvature relationship, bending stiffness of the modified joint is about 47% greater than the stiffness of the proposed joint. Furthermore, the modified joint has about 32% greater bending strength than the proposed joint. Compared to specimens without the joint the modified joint has same or slightly higher bending strength, but about 37% lower bending stiffness.

For the joint connection of the precast steel grid composite decks, a prefabricated joint which is composed of a concrete shear key and high-tension bolts was already proposed. In this study, for the purpose of increasing the bending stiffness and bending strength of the proposed prefabricated joint section details of the proposed joint are modified, and through experimental tests the bending performance, such as stiffness and strength of a modified joint, are compared with those of the proposed joint.

This paper presents test results of bending and weld joint of the HSA800. HSA800 for the high performance steel has a minimum 800MPa tensile strength. HSA800 can effectively reduce the size and thickness of structural member for high-rise building. Bending test and weld joint test of HSA800 are conducted to verify fabrication and performance of steel pile. Test results show that HSA800 is appropriate to make a heavy wall steel pipe. The fracture is occurred at the base metal of weld joint which can exhibit strength higher than its base metal.

기존의 격자형 강합성 바닥판 이음부 상세는 후크형태의 철근 겹침이음 및 채움 콘크리트로 구성된다. 본 연구에서는 콘크리트 전단키와 고장력볼트로 구성된 이음부 형식에 대해 콘크리트 전단키 보강 유무를 실험변수로 휨성능평가 실험을 하였고, 그 결과를 기존 철근겹침 이음부의 휨성능과 비교 평가함으로써 기계적 연결방법에 의한 이음부 형식의 적용 가능성을 검토하였다. 실험결과의 비교 분석에 의하면, 기계적 연결방식에 의한 이음부의 최대내력이 약 30% ~ 60% 정도 더 큰 것으로 나타나서 강도 측면에서 더 우수함을 확인하였다. 모멘트-곡률 관계로부터 구한 휨강성을 비교해 보면, 철근겹침 이음부의 경우 초기 거동에서는 비교적 더 우수한 거동을 보였으나, 콘크리트 균열파괴가 발생한 이후에는 다소 급격한 단면성능의 감소를 보였다. 한편, 콘크리트 전단키의 강판 보강 유무에 따른 변수 분석 결과에 의하면 강판 보강구조가 최대내력 향상 및 휨강성 증가에 효과적임을 확인할 수 있었다.