Izolarea structurii la masinile si echipamentele tehnologice cu actiune vibranta este o problema foarte importanta care trebuie rezolvata inca din etapa de proiectare. Aceasta are in vedere reducerea vibratiilor transmise operatorului uman, catre mediul inconjurator si echipamentului propriu-zis. Aceasta reducere a vibratiilor daunatoare trebuie sa se faca in contextul realizarii parametrilor tehnologici ai vibratiilor.
The problem of insulation is very important for the process equipments driving by vibrations. This means less vibrations transmitted to human operators, to the environment and to the equipment himself. Sometimes it have to know how to insulate undesired vibrations keeping the useful vibrations done by the driving system. This article leads to some criterion to obtain a dynamical insulation of vibrations without to decrease their technological parameters.

Dynamic damping of the machines and technological equipment driven by vibration

Problema reducerii vibratiilor generate de masini si utilaje este deosebit de vasta si comporta mai multe aspecte. Se cauta descoperirea de materiale vascoelastice noi, cu performante tehnice ridicate si capacitate de amortizare eficienta. Lucrarea prezinta analizarea covoarelor izolatoare cu diferite configuratii in scopul alegerii sistemului antivibrant optim la utilajele care produc socuri si vibratii in timpul functionarii, folosind analiza modala pentru obtinerea frecventelor naturale si modul de deformare al structurilor si analiza explicit dinamica, utilizind codul ANSYS.
The problem of reducing vibration generated by machinery is very large and involves many aspects. Are searching discovery of new viscoelastic materials with high technical performances and effective damping capacity. The paper presents the analysis of the characteristics of the isolation pads with different configurations for choice of optimal antivibration system for equipment whence producing shocks and vibrations during operation using modal analysis to obtain natural frequencies and mode of deformation structures and explicit dynamic analysis using ANSYS code.

Considerations about influence of the static and dynamic loads on the isolation pads

In lucrare se prezinta un studiu privind dinamica morilor vibratoare inertiale si se stabilesc parametrii regimului vibrator al acestora. Se prezinta, de asemenea, calculele necesare proiectarii generatorului de vibratii inertiale, cu mase excentrice in miscare de rotatie, utilizat pentru excitarea acestor tipuri de mori si sistemului elastic, format din elemente elastice din cauciuc, pentru rezemarea echipajului mobil al morii.
This work presents a study on the dynamics of inertial vibrating mills. The parameters of their vibrating regime are established too. The required computations for the design of inertial vibration generators with eccentrically rotating masses (used for the above mentioned type of mills) and of the elastic system (made up from rubber elastic elements required by the bearing devices of the mobile part of the mill).

Design of vibratory mills with rubber bearing system

Sunt prezentate caracteristici mecanice esentiale ale aliajului pe baza de cobalt HS 188, caracteristici investigate in cadrul unui proiect de studiu al Institutului National de Cercetari Aerospatiale referitor la evaluarea comparativa a unor aliaje recomandate spre a fi optionate in proiecte de constructii de aeronave. Concludenta rezultatelor obtinute la masuratori a argumentat recomandarile facute beneficiarului acestui proiect.
The HS 188 on a basis of cobalt alloy essential mechanic characteristics are submitted, characteristics investigated as part of the Aerospace Research National Institute study project concerning the comparative evaluation of some recommended alloys to be used in aerospace constructions projects. The measured obtained results conclusivity argued the recommendations concluded to this project beneficiar.

Expertise of cobalt alloys to be used for strength structures case studies

Aceasta lucrare studiaza modul in care oamenii percep vibratiile induse de un vehicul in miscare, pornind de la Legea puterii a lui Stevens. Marimea fizica masurabila a fost acceleratia transmisa sistemului mina-brat. Mssuratorile au fost facute cu 01dB MEASTRO. Un nou model a fost dezvoltat, bazat pe rezultatele acestui experiment. Modelul conceptual prezentat include cresterea disconfortului odata cu cresterea amplitudinii vibratiilor, precum si cu durata de expunere.
This paper studies the way humans perceive vibrations induces by a running vehicle, starting from the Stevens’ Power Law. The measurable physical magnitude was the acceleration transmitted to the hand-arm system. The measurements were made with MEASTRO 01dB. A new model was developed, based on the results of this experiment. The conceptual model presented included an increase in discomfort with vibration magnitude as well as an increase in discomfort with duration of exposure.

Experimental studies on the perception of vibration generated by construction equipment on humans

Sistemele de vibroizolare ale masinilor dinamice caracteristice domeniului de masini si utilaje pentru constructii şi nu numai, implica utilizarea unor elemente amortizoare cu diverse forme si dimensiuni; una din solutiile cel mai des intilnite este reprezentata de elementul de tip arc, dezvoltari ulterioare punind accentul pe utilizarea unor sisteme de bare (cabluri flexibile) cu comportament asemanator. Articolul de fata prezinta algoritmul de calcul pentru estimarea starii de tensiune si deformatie in cazul unui element semicircular incarcat normal pe planul sau, rezultatele obtinute fiind comparate cu marimile finale oferite de metode numerice alternative.
The damping elements used in shock and vibration attenuation came in various shapes and sizes; however one of the most common solutions being the spring shape, recent developements are using steel cable frames with beam-like behaviour. The present paper is focused on elementary strenght of materials calculus concerning stress and deflection state versus finite element analysis results for a simple curve shaped beam example.

Comparative stress and deflection state evaluation study concerning dynamic equipment shock and vibration damping elements