Dynamics of tactile device drive

A study of novel tactile device transient processes that occurs during the information transmission has been described. Mathematical model has been presented and investigation of pin drive dynamics were performed. Results of investigations allowed us to evaluate the influence of drive parameters and operating regimes on the pin motion, and may be used in engineering practice for tactile device developmen

Loading characteristics of weight stack machines

The load characteristics of the weight stack machines, where the resistance is generated by inertia of the stack of masses, are the subject of the paper. The method and means of experimental research are described. The dependencies of inertial resistance load upon the rate of exercises and the stack weight are determine

Evaluating the joinability of thin-walled high pressure die cast aluminium for automotive structures using self-piercing rivets

This paper is the first to report successful application of self-pierce riveting (SPR) in thin-walled high pressure die cast (HPDC) aluminium for use in automotive applications. HPDC fabricated AA356x coupons were joined to conventional rolled RC5754 material. A set of industry-relevant joint stacks were created. Priority stacks included cast material as the upper layer. More challenging joints were also fabricated with cast material as the lower layer. Automotive industry key performance indicators were used to assess joint integrity. The key results and recommendations were: • HPDC aluminium was revealed to be able to be joined to rolled aluminium according to vehicle manufacturer automotive standards. • Process boundaries were established for satisfactory SPR joints across a range of material thicknesses and stack types. • SPR joint solutions were proven in the most challenging stacks with cast material as a bottom layer. • Greater variability in the joint key performance indicators was observed in stacks where the cast alloy is the top layer. • Microstructural analysis of both AA356x and RC5754 revealed differences in grain structure and hardness and it is proposed that this accounts for the increased variability. • Strength testing of lap shear joints demonstrated the mechanical effectiveness of an SPR joint including cast material. Under normal vehicle operating conditions, the performance of joints including cast material was equivalent to that of rolled material only joints. Following yielding, joints including cast material suffered a more brittle failure mode leading to differences in performance under crash scenarios

Dielectric Dispersion in Ferroelectric Glycine Phosphite

Dielectric dispersion in ferroelectric hydrogen bonded glicyne phosphite crystal was investigated in the frequency range 100 Hz - 27 GHz. Dielectric relaxation of Debye type observed in the paraelectric phase shows a critical slowing down of the polarization fluctuations. The relaxation frequency decreases with temperature according to f$\text{}_{s}$ = 0.305(T-T$\text{}_{0}$) GHz in the paraelectric phase. The activation energy for flipping dipole motion ΔU = 2.07kT$\text{}_{c}$ confirms order-disorder character of the phase transition. In the ferroelectric phase pronounced low frequency (100 Hz - 1 MHz) dispersion related to domain contribution to permittivity was found

Investigation of the piezoelectric thimble tactile device operating modes

A multifunctional device to transfer graphical or text information for blind or visually impaired is presented. The prototype using tactile perception has been designed where information displayed on the screen of electronic device (mobile phone, PC) is transferred by oscillating needle, touching the fingertip. Having the aim to define optimal parameters of the fingertip excitation by needle, the computational analysis of different excitation modes has been carried out. A 3D solid computational finite element model of the skin segment, comprising four main fingertip skin layers (stratum corneum, epidermis, dermis and hypodermis) was built by using ANSYS Workbench FEA software. Harmonic analysis of its stress–strain state under excitation with different frequency (up to 10000 Hz) and harmonic force (0.01 N), acting outer stratum corneum layer in normal direction at one, two or three points has been performed. The influence of the mode of dynamic loading of skin was evaluated (in terms of the tactile signal level) on the basis of the normal and shear elastic strain in dermis, where mechanoreceptors are placed. It is shown that the tactile perception of information, delivered by three vibrating pins, may be influenced by configuration of excitation points (their number and phase of loading) and the frequency of excitation