• Advances in materials Research
• /
• v.8 no.4
• /
• pp.337-359
• /
• 2019

Shape Memory Polymer Composites (SMPC) have gained popularity over the last few decades due to its flexible shape memory behaviour over wide range of strains and temperatures. In this paper, non-linear bending analysis has been carried out for SMPC beam under the application of uniformly distributed transverse load (UDL). Simplified C⁰ continuity Finite Element Method (FEM) based on Higher Order Shear Deformation Theory (HSDT) has been adopted for flexural analysis of SMPC. The numerical solutions are obtained by iterative Newton Raphson method. Material properties of SMPC with Shape Memory Polymer (SMP) as matrix and carbon fibre as reinforcements, have been calculated by theory of volume averaging. Effect of temperature on SMPC has been evaluated for numerous parameters for instance number of layers, aspect ratio, boundary conditions, volume fraction of carbon fiber and laminate stacking orientation. Moreover, deflection profile over unit length and behavior of stresses across thickness are also presented to elaborate the effect of glass transition temperature (T_g). Present study provides detailed explanation on effect of different parameters on the bending of SMPC beam for large strain over a broad span of temperature from 273-373K, which encompasses glass transition region of SMPC.

• Journal of Powder Materials
• /
• v.4 no.4
• /
• pp.258-267
• /
• 1997

The powder forging process is an attractive manufacturing route for bevel gears. It offers beneficial material utilization and the minimization of finishing operations over that of conventional hot forging. The paper describes the process conditions for the powder forging of bevel gear, for example, powder alloy design, preform design, deformation of sintered preform, forging processes. The characteristics of prototype gear are investigated with microstructure, the density distribution, surface roughness of tooth, bending strength test of tooth, etc. The results of the bending strength test may prove the mechanical properties of powder forged gear.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1999.03b
• /
• pp.39-44
• /
• 1999

Hydroforming is a forming process enabling circular metal tubes to be produced in complex cross sections along curved axial paths With the availability of advanced machine design and control They offer advantages over stamped sheet metal in lower tooling cost and structural mass The technology is relatively new so that there is no large knowledge base to assist the fundamentals of tube hydroforming technology. The purpose of this paper is found that adaptive bending condition and contact condition for bended part has uniform thickness distribution.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.21 no.6
• /
• pp.778-783
• /
• 2015

We studied about the strength characteristics of the FRP bonding method due to reduce accident on the oceans and protect life for my people. We test tension and bending strength of butt joint, lap joint, V-scarf joint, X-scarf joint. The result of test, it's pattern is similar both tension and bending strength. Tension strength and bending strength was excellent in order to X-scarf-butt joint-V-scarf-lap joint. The tension strength is the best properties X-scarf showed a 57% strength rate of the basic material, and bending strength showed a 77% strength rate of the basic material. Overall, the X-scarf 12t joint has most excellent properties of tension and bending strength. The lap joint has worst properties of tension and bending strength. We have to test having different over-lay of V-scarf and X-scarf joint each 12t, 16t, 20t. V-scarf of 20t over-lay has excellent character of tension and bending strength. But X-scarf of 12t over-lay has excellent character of tension and bending strength. The results are shown to the contrary. The ship is received a lot of stress. it's hard to compare a direction both actual and test. But we can acknowledge material basic characteristic of strength through tension and bending test. We give the four repair method; butt joint, lap joint, V-scarf joint, X-scarf joint and the reduced ratio in comparison with basic material; In addition give the separated data for V-scarf and X-scarf characteristic of 12t, 16t, 20t overlay length. For our study repair man can select good repair method in his work station.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.10 no.6
• /
• pp.56-62
• /
• 2011

In this study, a method for the press forming of rectangular aluminium tube has been proposed. Rectangular aluminium tube has high stiff as the cold steel which can be lighter over 30% weight. It is increased every year by being recycled over 80%. Press die consists of punch, wing-die and holder for aluminium tube bending. When punch is applied with aluminium tube, holder is operated as same punch and wing-die is rotated through hinge. Stress-strain relations and springback are considered by bending angle of aluminium tube. In this study, the behaviors on tubes of square aluminium and rectangular aluminium with different thickness and area are established by the analysis of $DEFORM^{TM}$-3D program. Reducing fuel consumption is expected by using the aluminium tube deformation and it becomes the lightweight through recycling.

• The korean journal of orthodontics
• /
• v.36 no.5
• /
• pp.349-359
• /
• 2006

Objective: Nickel-titanium alloy wire possesses excellent spring-back properties, shape memory and super-elasticity. In order to adapt this wire to clinical use, it is necessary to bend as well as to control its super-elastic force. The purpose of this study is to evaluate the effects of heat treatment on the load-deflection properties and transitional temperature range (TTR) of nickel-titanium wires. Methods: Nickel-titanium wires of different diameters ($0.016"\;{\times}\;0.022"$, $0.018"\;{\times}\;0.025"$ and $0.0215"\;{\times}\;0.028"$) were used. The samples were divided into 4 groups as follows: group 4, posterior segment of archwire (24 mm) without heat treatment; group 2, posterior segment of archwire (24 mm) with heat treatment only; group 3, anterior segment with bending and heat treatment; group 4, anterior segment with bending and 1 sec over heat treatment. Three point bending test was used to evaluate the change in load-deflection curve and obtained DSC (different scanning calorimetry) to check changes in $A_f$ temperature. Results: In the three point bending test, nickel-titanium wires with heat treatment only had higher load-deflection curve and loading and unloading plateau than nickel-titanium wires without heat treatment. Nickel-titanium wires with heat treatment had lower Af temperature than nickel-titanium wires without heat treatment. Nickel-titanium wires with heat treatment and bending had higher load-deflection curve than nickel- titanium wires with heat treatment and nickel-titanium wires without heat treatment. Nickel-titanium with heat treatment of over 1 sec and bending had the highest load-deflection curve. Nickel-titanium wires with heat treatment and bending had lower Af temperature, Nickel-titanium wires with heat treatment of over Af sec and bending had the lowest Af temperature. Conclusion: From the results of this study, it can be stated that heat treatment for bending of Nickel-titanium wires does not deprive the superelastic property but can cause increased force magnitude due to a higher load-deflection curve.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2009.10a
• /
• pp.293-296
• /
• 2009

In roll forming process, a sheet metal is continuously progressively formed into a product with required cross-section and longitudinal shape, such as a circular tube with required diameter, wall-thickness and straightness, by passing through a series of forming rolls in arranged in tandem. In recent years, that process is often applied to the bumper rail in the automotive industries. In this study, a optimal front side member manufacturing technology, model deign and proper roll-pass sequences can be suggested by forming number of roll-pass and bending angle. And also effects of the process parameters on the final shape formed by roll forming defects were evaluated.

• Advances in materials Research
• /
• v.5 no.1
• /
• pp.35-53
• /
• 2016

Flexural bending analysis of perfect and imperfect functionally graded materials plates under hygro-thermo-mechanical loading are investigated in this present paper. Due to technical problems during FGM fabrication, porosities and micro-voids can be created inside FGM samples which may lead to the reduction in density and strength of materials. In this investigation, the FGM plates are assumed to have even and uneven distributions of porosities over the plate cross-section. The modified rule of mixture is used to approximate material properties of the FGM plates including the porosity volume fraction. In order the elastic coefficients, thermal coefficient and moisture expansion coefficient of the plate are assumed to be graded in the thickness direction. The elastic foundation is modeled as two-parameter Pasternak foundation. The equilibrium equations are given and a number of examples are solved to illustrate bending response of Metal-Ceramic plates subjected to hygro-thermo-mechanical effects and resting on elastic foundations. The influences played by many parameters are investigated.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2000.04a
• /
• pp.139-142
• /
• 2000

The SiCp/AC8A composites were fabricated by the pressureless metal infiltration process successfully. The effect of additional Mg, which were mixed with SiC particles to promote interfacial wetting between the reinforcement and matrix alloy, and particle size on the mechanical properties was investigated. By increasing the additional Mg content the hardness of SiCp/AC8A composites was increased due to the hard reaction products, but the bending strength was decreased by the excess reaction of Mg and high porosity level when the additional Mg content is over 7%. The Hardness and bending strength was increased by decreasing the size of SiC particle.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.05a
• /
• pp.754-757
• /
• 2004

This study was performed to propose design bending moment formula for long-span slab on a composite two-girder bridge. FEM models representing slab spaning between 4m and 12m were analyzed, and parameters such as girder flexibility and orthotropy of slab were considered. By regression of the parametric analyses results, the moment formula that can predict the design moment with reasonable margin of safety and correctness was developed. The research also showed that the design bending moment from Korean Bridge Design Code overestimated the design moment for the span length under gm, and underestimated for the span length over 9m.