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In recent decades, modeling of soft fingertips has fascinated a superior momentum in research initiatives concerned with development of an anthropomorphic soft finger tip. In design and development of soft fingertips, analysis of contact a characteristic plays a vital role on dexterous manipulation. This research work presents the results of the experimental investigation in relation to the formulations of contact area for soft fingertips pressed against assorted target profiles. A dimensionless parameter, curve factor Y (r/R) is introduced to derive a parametric relationship among the key parameters. It also addresses the growth of contact area of fingertips for five different combinations. From experimental observations, a modified power law equation with conversion factor (X) is proposed to interpolate the magnitude of contact area for different profiles.

In recent decades, research on soft robot manipulations and their materials attracted a huge momentum among various researchers. Selection of appropriate soft material is a vital role in robotic fingertip design, which enables the object to be held in proper orientation without slip and damage. Development of such an anthropomorphic type of soft hand requires knowledge about material selection, types of finger contact and the mechanism behind grasping. This research work presents a comprehensive comparison of six chosen soft materials with human skin for improved robotic manipulation. Extensive research is required to develop such soft hands for better manipulation becausein the final analysis, the human hand is the best soft manipulator as it conforms to objects easily through good contact with an object. In the past decades, many researchers have tried to replace metal hand of robots with appropriate soft materials to enable better manipulation. In this work, the magnitude of contact area, contact pressure and vertical depression of six soft materials was compared with human skin with respect to precision grasping. The simulation results clearly show that neoprene rubber exhibits a close relationship with the characteristics of human skin.

The prime objective of this research work is focused on assessing the dynamic characteristics of a multi core sandwich composite beam with cutouts.The effect of introducing additional cores in sandwich beams is investigated in detail along with various geometric configurations. Also, the impact of placing multiple cutouts with assorted geometric profiles (Circular, Square, Hexagon and Triangular) in a sandwich structure is also addressed in detail. Finite element technique is deployed for numerical analysis and parametric studies. In addition, the influence of reinforcements in the proposed structure is also presented. From the results, it is evident that square cutouts possess the highest damping capability irrespective of geometric position of its placement. Also, it may be concluded that the geometric position of placing cutoutssignificantly influences the magnitude of frequency levels ranging to maximum of 42% hike at lower modes.Moreover, introduction of cutouts leads to reduction in frequency levels for all the cases up to 20%. Furthermore, secondary investigation of multicore reinforced sandwich beams experiences a maximum reduction in frequency of about 15%.

This paper presents a finite element study on the contact parameters of a soft hemispherical finger tip pressed against curved surface. The variation in magnitudes of contact radius, contact pressure and vertical displacement are estimated using two-dimensional finite element models. The special effects of geometry using a wide range of normal force on soft finger tips are presented with the aid of a dimensionless parameter, curve factor (R/a). It addresses the effects of the load–contact relationship for ten different fingertip combinations. From close observations it can be concluded that a higher magnitude of contact radius can be obtained with a lower curve factor and vice-versa. Also, it is evident that the radius of contact is higher for a curved object when compared with a flat one for a particular combination. However, there is a significant reduction in the magnitudes of vertical depression and contact pressure.

The main purpose of the present work is to develop an artificial fingertip comprised of a soft layer and an inner rigid core, which emulates a human one with skin and bone. The influences of introducing the core and the effects of variations in thickness of the soft layer over the contact parameters are investigated. From the results, it is evident that the power law theory proposed by (Xydas N, Kao I. Int. J. Rob. Res. 1999, 18, 941–950) becomes invalid in this criterion; by contrast, if the power law theory acts for finger tips with internal cores, the conclusion may be redefined in such a way that the soft material behaves more softly in the presence of internal cores and the dimensionless number, core-soft layer coefficient Fcs≈0.5, is the critical parameter which produces the change of behavior. Moreover, soft finger tips with an inner core are preferable to entirely soft ones, as a higher grasping stability is achieved with the same area of contact, and the conforming nature of the fingers is maintained.

This work aims at estimating and comparing the frequency and loss factor of a mild steel sandwich shaft disc system containing viscoelastic, electro-rheological fluid (ERF), and magneto-rheological fluid (MRF) core materials with mild steel as the facing layers. Because the structure is axisymmetric, a semi-analytical finite element method was implemented to study the frequency and loss factor values of the mild steel sandwich shaft disc system. The effects of an electric field for the ERF material and a magnetic field for the MRF material on the vibration behavior of the mild steel sandwich shaft disc system were studied. A quantitative study identified the combination of mild steel facing with a viscoelastic core shaft disc system that produced the highest frequency and loss factor values. In addition, the effect of an electric field and a magnetic field on ERF and MRF core improves the damping performance of the structure.

Modeling of soft finger contact mechanics is a prerequisite for gripper design. Realism of soft finger deformations depends extremely on the selection of appropriate hyper-elastic material model for soft materials. The essential criterion for a good mathematical model for hyper elasticity is its ability to match the measured strain energy curves under different deformations over a large range. Selecting an appropriate material law for a given material combination is one of the most difficult tasks in soft finger contact modeling. The present study is devoted for comparing seven popular hyper-elastic non-linear material models (Mooney–Rivlin, Ogden, Yeoh, Neo-Hookean, Gent, Polynomial and Aruda–Boyce model) and selection of the most appropriate model based on experimental data for modeling of soft contact problems. Present results clearly reveal that Ogden and Neo-Hookean model are more suitable for these problems and in line with the experimental results. Finite element technique is employed for critical comparison of various hyper-elastic material models.

Computer-aided process planning (CAPP) is an important interface between computer-aided design (CAD) and computer-aided manufacturing (CAM) in computer-integrated manufacturing environment. A problem in traditional CAPP system is that the multiple planning tasks are treated in a linear approach. This leads to an over constrained overall solution space and the final solution is normally far from optimal or even non-feasible. The operation-sequencing problem in process planning is considered to produce a part with the objective of minimizing the sum of machine, setup and tool change costs. In general, the problem has combinatorial characteristics and complex precedence relations, which makes the problem more difficult to solve. In this paper, the feasible sequences of operations are generated based on the precedence cost matrix and reward–penalty matrix using simulated annealing technique (SAT), a meta-heuristic. A number of benchmark case studies are carried out to demonstrate the feasibility and robustness of the proposed algorithm. This algorithm performs well on all the test problems, exceeding or matching the solution quality of the results reported in the literature for most problems. The main contribution of this work focuses on reducing the optimal cost with a lesser computational time along with generation of more alternate optimal feasible sequences. The proposed SAT integrates robustness, convergence and trapping out of local minima.