scholarly journals A Design Insight for Substitution of Metal Shims with Reverse Engineered Element in Tool Post for Alignment of Tool-Work Center

2020 ◽  
Vol 3 (1) ◽  
pp. 114-129
Author(s):  
Surabhi Lata ◽  
Hitesh

This research work propounds and analyses the comparison of solution to the issue of height adjustment of tool in four way tool post. The customary way of tool lifting in tool post to centre of work i.e. by adding/removing metal packing, is altered by introducing a design alternative for tool lifting, an upgradation in the former proposed design named solid double cone threaded pin (SDCTP). It is explicitly studied to investigate its limitation and scope for further design amendments. In the premise, a revised design is proposed including modifications named as solid cone threaded pin (SCTP) and is fabricated along with its assembly. Mathematical calculations of least count and screw thread analysis are performed on both the pins. Finite element analysis on CREO is executed to calculate stresses induced for diverse loads to analyze pin failure conditions. The results of new modified design is compared with the erstwhile concluding that SCTP design is preferable over SDCTP design entailing precise tool adjustment, saving time and higher efficiency in machining operations. The paper subsequently explores conventional tool lifting method and its shortfall, shortcomings of former design, revised design and its comparison, fabrication of revised design, conclusions and future ambit.

Author(s):  
Saurabh Srivastava ◽  
Sachin Salunkhe ◽  
Sarang Pande ◽  
Bhavin Kapadiya

Steering knuckle connects steering system, suspension system and braking system to the chassis. The steering knuckle contributes a significant weight to the total weight of a vehicle. Increasing the efficiency of an automobile without compromising the performances is the major challenge faced by the manufacturers. This paper presents an effective topology optimization of steering knuckle used in a vehicle with the primary objective of minimizing weight. The study on optimization of knuckle is divided into two phases, the first phase involves making of a computer-aided design model of the original steering knuckle and carry out finite element analysis on the knuckle by estimating the loads, which are acting on the component. In the second phase, design optimization of the model of steering knuckle is carried out, and excess material is removed at the region where induced stress is negligible as obtained in finite element analysis assuming standard boundary and loading conditions. The paper describes a research work carried out to optimize structural topology giving the essential details. The methodology may be applied to optimize structural components used in applications where the ratio of desired properties to the cost, generally in terms of weight, is to be optimized. In the case of automobiles, strength to weight ratio has to be maximized. New researchers working in the area will have an understanding of the procedures, and further, the techniques may be applied to design in general.


2017 ◽  
Vol 69 (1) ◽  
pp. 30-41 ◽  
Author(s):  
Mitul Thakorbhai Solanki ◽  
Dipak Vakharia

Purpose The purpose of this paper is to present a finite element analysis (FEA) which shows the comparison between a layered cylindrical hollow roller bearing and hollow roller bearing. Design/methodology/approach In this work, FEA is carried out to solve the elastic contact between a layered cylindrical hollow roller and flat contact for different hollowness percentages ranging from 10 to 80 per cent. Graphical solution is developed to determine the optimum hollowness of a cylindrical roller bearing for which induced bending stress should be within endurance limit of the material. Findings Different parameters such as von Mises stress, contact pressure, contact width and deformation are shown here. Originality/value The value of this research work is the calculation of contact width and other parameters using FEA for layered cylindrical hollow roller bearing.


Author(s):  
Yuya Omiya ◽  
Tadatoshi Watanabe ◽  
Masahiro Fujii ◽  
Haruka Yamamoto

In this study, the creep deformation in the threaded joint are discussed using a finite element method, and evaluated the influence of the dimensions of bolt and clamped parts. The stress and creep strain distributions are calculated using the Finite Element Analysis. The occurrence and the propagation of the creep deformation and influence of the creep deformation on the axial bolt force were discussed. It was found that the creep deformation occurred at the bearing surfaces and the engagement screw thread mainly at the elevated temperature. The creep deformation was a cause of the reduction in axial bolt force.


Author(s):  
A. Carnero ◽  
J. Kubiak ◽  
A. López

Abstract Frequent failures of long turbine blades forced an electrical utility to sponsor research work to find out the causes of the failures. One of the techniques applied in this work was finite element analysis. The paper presents an application of the finite element method for computation of the natural frequencies, steady-state and alternating stresses, deformations due to forces acting on the blades and modal shapes of the turbine long blade groups. Two stages, L-1 and L-0 of the low pressure part of a steam turbine, were analyzed. It has been postulated that the results of the FEM analysis of the blades groups would be complementary to those obtained from the radio telemetry test (which was carried out during operation of the turbine) for the purpose of blade group failure diagnosis. However, the results of the analysis show that the FEM results were decisive in blade failure identification (L-1 stage moving blades). The graphical post processor of the FEM code revealed that the first blade in the group was the one most protruding from the stage rotating plane, thus indicating that this blade was the most prone to erosion. This was confirmed in the inspection of the turbine. This finding showed why only the first blade in the group was cracked (erosion induced cracks). The mode shapes were also very helpful in identifying other types of cracks which affected other parts of the blades. It can be concluded that the finite element method is very useful for identification of very difficult cases of blade faults and indispensable for carrying out modifications to prevent future failures.


2016 ◽  
Vol 51 (6) ◽  
pp. 733-743
Author(s):  
Muhammad Owais Raza Siddiqui ◽  
Danmei Sun

The thermal property of textile structures plays an important role in the understanding of thermal behaviour of the clothing. In this work, user-friendly GUI plug-ins have been developed to generate both microscopic and mesoscopic scale models for finite element analysis. The plug-ins were developed by using Abaqus/CAE as a platform. The GUI Plug-ins enable automatic model generation and prediction of the effective thermal conductivity of woven composite and microencapsulated Phase Change Materials composites via finite element analysis by applying boundary conditions. The predicted effective thermal conductivities from plug-ins have been compared with the results obtained from published experimental research work based on an established mathematical model. They are correlated well. Moreover, the influence of phase change materials on heat transfer behaviour of microencapsulated Phase Change Materials composites was further analysed.


2016 ◽  
Vol 8 (12) ◽  
pp. 168781401668265 ◽  
Author(s):  
Dongmei Zhang ◽  
Shiqiao Gao ◽  
Xiao Xu

For designing bolted connections in machinery applications, it is necessary to estimate the stiffness of the threaded connection. This work provides a new method for computing the stiffness of engaged screw in bolted connections according to the load distribution in screw thread. Finite element analysis is performed by building the three-dimensional model of threaded connection. A set of tensile tests are exerted to validate the accuracy of the suggested model of threaded connection. A good agreement is obtained when the analytical results are compared with finite element analysis results, experimental data, and Yamamoto method. Results reveal that the ultimate strength of thread connections is obviously lower than that of thread material. In addition, the results of calculation and finite element analysis indicated that increasing Young’s modulus of material and the engaged length or decreasing thread pitch could increase the stiffness of the thread portion of a bolt and nut.


2010 ◽  
Vol 145 ◽  
pp. 278-281
Author(s):  
Zheng Yi Wang ◽  
Lian Yun Jiang ◽  
Chun Jiang Zhao

Owning to the unreasonable structural design of the rolling mill’s pressure screw, there is severe stress concentration on the top and the root of the screw thread, which make their abrasion seriously. Therefore the service life and accuracy of the pressure screw will decrease a lot. In the article, based on analysis of the structural parameters and material parameter of the pressure screw, we get the factors which will affect the contact stress between the screw thread. By the method, the contact stress between the screw thread is well-distributed, which will helpful for the designers


Author(s):  
Mosfequr Rahman ◽  
Steven Chrysosferidis ◽  
Sirajus Salekeen ◽  
Adam Chevalier ◽  
David Bell ◽  
...  

The objective of this research work was to perform a flow simulation around a running bullet and then compare and analyze three types of widely used bullet models. These are 7.62mm × 39mm, 7.62mm × 51mm, and 5.56mm × 45mm caliber popular NATO rounds respectively. Due to limited processing and computational resources, these bullet are modeled as cylindrical projectiles of similar length and diameter. Finite element analysis (FEA) are performed on these models using ANSYS explicit dynamics analysis code to investigate the effect of high velocity impact of these projectiles on a concrete plate. Three different types of meshing (coarse, fine, and fine with curvature) for each of these three cases have been used. Each projectile was fired at a different velocity. These velocities are selected in consultation with Hornady Manufacturing, Inc which has done extensive research on these bullets. The selected firing velocities for 7.62mm × 39mm, 7.62mm × 51mm, and 5.56mm × 45mm caliber bullets are 2021ft/s, 2539.4ft/s 2706.7ft/s respectively. Overall, the simulation result of explicit dynamics clearly demonstrated cavitation and mushrooming of projectiles when impacting a 0.25 inch concrete plate. The 5.56mm × 45mm projectile seemed to have the largest overall total deformation values of 2.0303, 1.0487, and 0.26079 feet as obtained from simulation of the three types of mashing. This can be attributed due to the higher velocity (2706.7ft/sec) as compared to the other two cases. Similarly, the 7.63mm × 39mm has the highest average change of velocity of 144.7, 92.3, and 99.6ft/sec respectively from the three types of meshing among the three bullets which can be attributed due to its lowest impact velocity (2021ft/s).


Author(s):  
R Zdero ◽  
M Olsen ◽  
H Bougherara ◽  
E H Schemitsch

Biomechanical assessments of orthopaedic fracture fixation constructs are increasingly using commercially available analogues such as the fourth-generation composite femur (4GCF). The aim of this study was to compare cancellous screw purchase directly between these surrogates and human femurs, which has not been done previously. Synthetic and human femurs each had one orthopaedic cancellous screw (major diameter, 6.5 mm) inserted along the femoral neck axis and into the spongy bone of the femoral head to a depth of 30 mm. Screws were removed to obtain pull-out force, shear stress, and energy values. The three experimental study groups ( n = 6 femurs each) were the 4GCF with a ‘solid’ cancellous matrix, the 4GCF with a ‘cellular’ cancellous matrix, and human femurs. Moreover, a finite element model was developed on the basis of the material properties and anatomical geometry of the two synthetic femurs in order to assess cancellous screw purchase. The results for force, shear stress, and energy respectively were as follows: 4GCF solid femurs, 926.47 ± 66.76 N, 2.84 ± 0.20 MPa, and 0.57 ± 0.04 J; 4GCF cellular femurs, 1409.64 ± 133.36 N, 4.31 ± 0.41 MPa, and 0.99 ± 0.13 J; human femurs, 1523.29 ± 1380.15 N, 4.66 ± 4.22 MPa, and 2.78 ± 3.61 J. No statistical differences were noted when comparing the three experimental groups for pull-out force ( p = 0.413), shear stress ( p = 0.412), or energy ( p = 0.185). The 4GCF with either a ‘solid’ or ‘cellular’ cancellous matrix is a good biomechanical analogue to the human femur at the screw thread—bone interface. This is the first study to perform a three-way investigation of cancellous screw purchase using 4GCFs, human femurs, and finite element analysis.


2008 ◽  
Vol 575-578 ◽  
pp. 322-327
Author(s):  
Dong Gyu Ahn ◽  
Hyun Soo Moon

The objective of this research work is to design optimally dies and the blank sheet for manufacturing of the back panel of a PDP TV. The influence of design parameters of the dies and the blank sheet on the formation of wrinkling in the upper trimming area of the stamped part has been quantitatively investigated through three-dimensional elasto-plastic finite element analysis. The corner radius of the upper trimming area of the die and the blank gap, which is the distance from the outer line of the blank holder to that of the blank, have been chosen as design parameters to remove wrinkling associated with a stamping part in a upper trimming area. From the results of the analyses, it has been shown that a product without wrinkles and skid lines can be manufactured when the corner radius is 8 mm and the blank gap is 60 mm. Several stamping tests have been performed using the manufactured die set and the blank sheet according to the proposed optimum design. From the results of the stamping tests, it has been shown that a back panel of the PDP TV can be successfully manufactured using the proposed optimum design condition.


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