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Advances in digital fabrication have simultaneously created new capabilities while reinforcing outdated workflows that constrain how, and by whom, these fabrication tools are used. In this paper, we investigate how a new class of hybrid-controlled machines can collaborate with novice and expert users alike to yield a more lucid making experience. We demonstrate these ideas through our system, Turn-by-Wire. By combining the capabilities of a traditional lathe with haptic input controllers that modulate both position and force, we detail a series of novel interaction metaphors that invite a more fluid making process spanning digital, model-centric, computer control, and embodied, adaptive, human control. We evaluate our system through a user study and discuss how these concepts generalize to other fabrication tools.

The manuscript aims to perform the free and forced vibration analysis considering the porosity and orthotropic foundation effect. For the first time, the study is conducted on a variable thickness FGM plate resting on an orthotropic foundation. This study uses the first-order shear deformation plate theory (FSDT) model to present an exact solution for free and forced vibration analysis of the functionally graded material (FGM) plate with variable thickness. The FGM plate, having exponentially varied material properties in the thickness direction, was restrained on simply supported (S-S-S-S) and clamped-clamped (C-C-C-C) boundary conditions. Three different types of microstructural defects (porosity) are taken into consideration during the establishment of the mathematical modeling. In addition, the effect of the orthotropic Pasternak foundation has been incorporated during the formulation. The governing differential equation for thick to thin plates is derived using a variational approach, and further, the Galerkin method is applied to solve the equation of motion. The results have been compared and validated with the existing literature available for a rectangular plate on an elastic foundation. The parametric studies have been done to explore the detailed understanding of the E-FGM (Exponentially graded material) plate including microstructural defects. Even the benchmark results have been investigated for free and forced vibration analysis of the E-FGM plate on the orthotropic elastic foundation. [ABSTRACT FROM AUTHOR]

The study presents transmissibility responses of 14 male subjects exposed to vertical sinusoidal vibration (2.0–16.0 Hz) at five vibration magnitudes (0.5–1.5 m s−2 r.m.s.). The vibration magnitudes are measured at five body locations: head (at the forehead), sternum, abdomen, thigh, and leg, for which the transmissibility at each body location is statistically analyzed. The nonlinearity in the transmissibility response, that is, decrease in resonance frequency with an increase in vibration magnitude, is evident for the sternum, abdomen, thigh, and leg. The higher vibration magnitude causes greater segmental transmissibility at excitation frequency lower than the resonance frequency. The highest vibration transmissibility has been observed for the abdomen, followed by the thigh, sternum, and head. The findings indicate that the higher energy content associated with the sinusoidal waveform further softens the tissues in contact with the vibrating surface. Practitioner Summary : The present study provides transmissibility responses of the semi-supine posture of humans at the head, sternum, abdomen, thigh, and leg under vertical sinusoidal excitation (2.0–16.0 Hz). Pronounced transmissibility is obtained for the abdomen among the other body segments, followed by the thigh, as both consist of a majority of soft tissues. [ABSTRACT FROM AUTHOR]

This paper attempts to demonstrate the vibration response of porous Functionally Graded Material (FGM) plate with variable thickness. For the first time, the porous tapered FGM plate being considered is mathematically modeled and assumed to be resting on a linear, parabolic, sinusoidal, and exponential varying Winkler's elastic foundation. The even and uneven porosity distribution as a micro-defect is assumed in a tapered FGM plate that varies according to well-defined mathematical rules. The tapered FGM plate, across the edges, is supported with various boundary conditions. Simple Power (P-) and Sigmoid (S-) Law have been chosen for the homogenization of material properties that are tailored in the thickness direction. First-order shear deformation theory (FSDT) is applied to describe the displacement function for computing the strain field. The variational approach has been used to establish the formulation for free vibration response. The equation of motion has been derived using Hamilton's principle and solved by implementing Galerkin Vlasov's method. Parametric studies on elastic foundations have been done to explore the results and relevance to the real problems. It was observed that variable foundation has a significant effect on the tapered FGM plate rather than the tapered homogenous plate. In addition, it was witnessed that the effect of variable foundation effect diminishes as a constraint on the edges of the tapered FGM plate increases. Also, some benchmark results based on the porosity effect and the influence of variable elastic foundations are exhibited in this study for future reference. [ABSTRACT FROM AUTHOR]

The present study proposes a 15-degrees of freedom multibody model of semi-supine humans to estimate the injury risk to a space capsule occupant during landing. The model consists of five body segments representing head-neck, thorax-arms, abdomen, thigh-pelvis, and leg. The semi-supine human model is calibrated using transmissibility responses of each body segment obtained from parallel vibration testing on the human subjects. The occupants' dynamic response to impact acceleration incurred during landing is simulated through the developed model. The model estimated the highest acceleration at the thorax and head, respectively, in the chest and spine directions. The impact acceleration of 20g is observed to violate the low injury risk criterion at the seat angle of 30°. The proposed human body model can be employed to design and test the effectiveness of attenuation and restraint systems of a space capsule. [ABSTRACT FROM AUTHOR]

A non-polynomial hyperbolic based theory has been presented for the free vibration response of a rectangular plate with linearly varying thickness, which rests on an elastic foundation. Ceramic/ metal has considered as Functionally Graded Material (FGM) of the plate using exponential law for material gradation of properties in the thickness direction. The influence of Winkler's and Pasternak's paremeter of foundation on the plate is investigated in conjunction with taper ratio. The governing equation of plates has established using the variational principle. Galerkin's technique has been followed for the solution of the eigen value problem of the presented model. The obtained results have compared with the observations of the isotropic tapered plate, and FGM plate for uniform thickness. The numerical result depicts the good accuracy of the present theory comparable to the existing shear deformation theory. The influences of thickness variation for a plate, has assumed to be simply supported and clamped, have investigated with various span ratio, aspect ratio, taper ratio and foundation stiffness. [ABSTRACT FROM AUTHOR]