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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 bio-mechanics of skin and bone play a crucial role in dexterous object manipulations and artificial robotic gripper design. Establishing a quantitative relationship between imposed loads and contact factors is necessary to understand the governing mechanics behind it. Towards this goal, experimental investigations on the contact parameters of a sandwich soft fingertip comprising a soft layer and solid core are presented. The influence of soft layer stratum and material grades on the power law equation is investigated by introducing a new dimensionless parameter – Power Factor. The results clearly indicate that the power index “γ” is dependent on the material as well as shell thickness and in addition the proportionality constant “C” is dependent on the geometry. Also, the magnitude of both the constants increases with power factor and saturates at a value of ≈1.25. Numerical simulation is performed to support the experimental results. Finally, an optimum ratio of power factor is determined and the number ≈1.25 is critical in designing the artificial robotic sandwich fingertip.

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.

The main aim of this paper is to investigate the effect of various constrained layers (viscoelastic layer (VEL), electro-rheological fluid (ERF), and magneto-rheological fluid (MRF)) over natural fre- quency and the damping loss factor with two different fiber orientations (0 and 90) for a Graphite/Epoxy (GR/E) composite sandwich shaft disc system. The finite element technique is used to investigate the natural frequency and loss factor for various combina- tions. Furthermore, the vibrational characteristics of the composite sandwich shaft disc system are compared with those of the base structure without constrained layers. The study shows that introducing various constrained layers reduces the magnitude of natural frequency by up to 80%. The results also show that GR/ E composite with 90 fiber orientation acquires the highest frequency reduction. Among the proposed layers, VEL has the highest damping loss factor.