Force In Transverse Direction Research Articles

Scrutinization of Stefan suction/blowing on thermal slip flow of ethylene glycol/water based hybrid ferro-fluid with nano-particles shape effect and partial slip

This study is aimed to examine thermal slip flow of mixture based hybrid ferro-fluid with shape effect of nano-particles and partial slip under the constant influence of Stefan suction/blowing impacts. Thermal slip flow is magnetized with applied time-dependent magnetic force in transverse direction of flow. Partial slip impact is considered on magnetized hybrid ferro-fluid. Additionally, spherical shaped nano-particles have been accounted to constitute the desired hybrid ferro-fluid whereas distinct shape nano-particle effect is analyzed and discussed for heat transfer efficiency. The flow governing highly nonlinear equations are transformed into ordinary differential equations using suitable similarity transform. Furthermore, motion and temperature profile for spherical shaped nano-particles of hybrid ferro-fluid are analyzed and discussed under the impression of suction and blowing effect. It is observed that in the event of mass suction S=1 and partial slip 0.2≤Sf≤0.6 reduced shear stress rates and high rates of heat transfer are obtained. It is concluded that high Lorentz force under suction/blowing effect contract thermal boundary of flow. Laminar shape nano-particle increase temperature profile when compared with other shapes of nano-particles.

Manufacturing of high strength plywood composites reinforced with copper fibers

Using wood as matrix phase layered composites are manufactured commercially, they are commonly known as plywood boards. There are many drawbacks for plywood boards like lack of strength and inefficiency to apply force in transverse direction. In this work we are trying to minimize these defects by making some changes in the manufacturing procedure. The first procedure is making holes in the matrix phase to make inter matrix bonds, which will help to improve the bond strength and apply force in lateral direction. The second procedure is introducing metallic nets to improve the load carrying capacity of the composite. The third procedure is the combination of the above two. Some design changes is required in drier to make holes in the green veneer, and there is also a change in table setting to introduce metallic net element. These procedures will help to produce high strength layered composites using wood as matrix phase with a minimum cost.

Three-dimensional assessment of transverse displacement with Facemask and Maxgym in unilateral cleft lip and palate model.

Growing patients with cleft lip and palate (CLP) exhibit maxillary deficiency due to early surgical intervention. Maxillary protraction with expansion is the recommended treatment modality for deficient maxilla. Facemask is a conventional protraction appliance, and Maxgym is a new protraction appliance. The purpose of this study is to compare the efficacy of Maxgym with Facemask using finite-element analysis. A three-dimensional finite-element model consisting of 49,807 nodes and 185,620 tetrahedral-shaped elements was created using computed tomography scan of a patient with unilateral CLP. F1, F2, and F3 represent different protraction forces of facemask, and M1, M2, and M3 represent different protraction forces of Maxgym. E1 represents slow maxillary expansion (SME) force, and E2 represents rapid maxillary expansion (RME) force. Facemask and Maxgym forces were applied parallel to the occlusal plane from the middle of the clinical crown on the buccal side of the first premolars. The forces E1 and E2 were also applied on the middle of the crown height on the lingual side of the first premolars and the first molars to simulate expansion. The amount of displacement for Maxgym and Facemask forces in transverse direction was analyzed designating specific nodes to represent dental and skeletal structures. The dental and skeletal structures were displaced in transverse direction under all loading conditions. Only expansion or protraction force resulted in transverse displacement of nodes. RME produces greater transverse displacement as compared to SME. Maxgym forces produce greater transverse displacement as compared to facemask. Maxgym with RME produces greater transverse displacement as compared to Maxgym with SME, whereas facemask with RME produces greater transverse displacement as compared to facemask with SME. Maxgym forces produce greater transverse displacement as compared to facemask with or without expansion.

Detailed load rating analyses of bridge populations using nonlinear finite element models and artificial neural networks

For assessing load rating capacity of bridges, American Association of State Highway and Transportation Officials Manual (AASHTO) recommends a simple method, where distribution of the forces in transverse direction is estimated by axle-load distribution factors on a simply supported beam. Although the method is practical in the sense that it allows for rapid evaluation of bridge populations, it leads to over-conservative load ratings. A finite element (FE) based load rating analysis is conceived as a more accurate strategy, yet the need for constructing and analyzing a FE model for every single bridge in the population makes it impractical for load rating analyses of a bridge population. In this study an efficient method is developed for detailed load rating analyses of bridge populations through nonlinear FE models and artificial neural networks (ANNs). In this method, geometric-replica 3D FE models are used for nonlinear response analyses and load rating calculations for a sample bridge set. ANNs are then trained to learn implicit relationships between the governing bridge parameters and the resulting load ratings using this sample bridge set, and to make cost-free load rating estimations for other bridges that are not included in the set. The single-span reinforced concrete T-beam bridge population in Pennsylvania State is used to demonstrate a practical case study for application of the method. The results indicate that FE based load rating calculation procedure integrated with ANNs can be used as efficient tools for in-depth condition assessment of bridge populations.

Shear Strength of Reinforced Concrete Beam Strengthened by Transverse External Post-tension

Problem statement: Shear failure of concrete beam is brittle manner without warning so inadequate design for shear of beam and/or material deterioration lead to the possibility of sudden failure of beam. The change of functional use and future increased load of structure lead to the need for strengthening of concrete structure. Approach: This research focuses on behaviors under static loading of reinforced concrete beam, with shear strengthening by transverse external prestressing force. Post-tension high strength steel is vertically applied in shear span. Total eight beam specimens are divided into two groups each having shear span to depth ratios 2 and 1.5. Each beam, possessing the same reinforcing steels, is intentionally designed to be failing in shear. One of the beams from each group is used as reference, without shear strengthening. The other three specimens from each group are applied different amounts of external prestressing force. Results: The experimental result shows that ultimate load carrying capacity of all shear strengthened specimens significantly improves over the reference specimen. The higher the amount of applied strengthening force, the greater the ability to carry ultimate loading. Failure mode shifts from brittle shear failure closer to ductile flexural failure, with higher ductility and stiffness. External prestressing force in transverse direction of shear span of beam enhances ultimate shear capacity by improving aggregate interlocking, preventing splitting cracks caused by debonding of longitudinal reinforcing steels due to dowel action. Furthermore, load at first diagonal tension cracks are increased as a result of pre-compressed prestressing force leading to the higher ultimate load carrying capacity. Moreover, concrete in compression zone remains uncrushed at ultimate state. Strut-and-tie model can be used to predict ultimate loading capacity of beam specimen and failure mechanism of both specimens with or without strengthening. Conclusion: Shear strength of reinforced concrete beams strengthened by transverse external post tension at shear span is effectively improved over reference beam specimen. Strut and tie model can be conservatively predicted the ultimate shear capacity of both reference and strengthened beam specimen.

木材横引張りにおける細胞壁内の応力分布

木材横引張りにおける細胞壁内の応力分布