Time filter

Source Type

Vitry-sur-Seine, France

Rublon P.,LRCCP | Favier A.,Metravib ACOEM Group
Constitutive Models for Rubber IX - Proceedings of the 9th European Conference on Constitutive Models for Rubbers, ECCMR | Year: 2015

Fatigue crack growth tests consist in measuring the propagation rate of a pre-existing flaw inserted in a sample, in opposition to the crack nucleation approach often studied. Such tests are performed at LRCCP on a DMA+300 fatigue machine developed by ACOEM, on “pure shear” samples. The purpose of this work is thus to evaluate the influence of various experimental parameters on the measured crack growth behaviour of a carbon black filled SBR. It includes the impact of the mechanical loading parameters (frequency, waveform…), and also material parameters (carbon black dispersion, curing system…). However, the only parameter considered in this paper is the effect of the antioxidants addition to the material formulation. Indeed, the comparison of fatigue crack growth rates measured on different samples, with various amounts of 6PPD (acting as antioxidant), before and after a thermal ageing, helps finally to determine how the fatigue crack growth behaviour is affected by this kind of chemical product. © 2015 Taylor & Francis Group, London, UK. Source

Omnes B.,CETIM | Heuillet P.,LRCCP
Constitutive Models for Rubber IX - Proceedings of the 9th European Conference on Constitutive Models for Rubbers, ECCMR | Year: 2015

This paper presents the recently studies carried out to improve the knowledge on the tightness of the rubber seal at low temperature, around −50°C. The thermomechanical behaviour, the evolution of the leakage through the temperature glass transition (Tg) and the study of different constitutive equations implemented in the finite element code, are the major items covered by this study. The experimental results obtained on the samples and the O-rings, have been compared to the numerical results. A hyper viscoelastic model with the Prony cells and Time-Temperature dependences has been chosen. The material parameters have been identified on a thermomechanical database. © 2015 Taylor and Francis Group. Source

Marco Y.,Ensta Bretagnelaboratoire Brestois Of Mecanique Et Des Systemes | Masquelier I.,Ensta Bretagnelaboratoire Brestois Of Mecanique Et Des Systemes | Le Saux V.,Ensta Bretagnelaboratoire Brestois Of Mecanique Et Des Systemes | Huneau B.,CNRS Research Institute in Civil Engineering and Mechanics | And 2 more authors.
Constitutive Models for Rubber IX - Proceedings of the 9th European Conference on Constitutive Models for Rubbers, ECCMR | Year: 2015

Because of the heterogeneous nature of these filled materials, the fatigue properties of elastomers are strongly connected to their microstructure. The goal of this study is to characterize the fatigue damage scenario at the inclusions’ scale. In a companion paper (Huneau et al., 2015) SEM techniques were applied to describe the early stages of initiation. Nevertheless, this description remains geometric and provides no local mechanical data. To overcome this limitation, thermal measurements at the microstructure scale are achieved and a specific protocol is applied to infer the dissipation fields from the temperature measurements. Formerly developed on a classical structural sample, this approach is applied to samples with well mastered typical flaws at the microscopic scale and then to samples exhibiting isolated carbon blacks agglomerates. The experimental results obtained are finally correlated to SEM observations, providing a precious database for the understanding and a quantitative evaluation of the initiation mechanisms induced by inclusions. © 2015 Taylor & Francis Group, London, UK. Source

Labban A.E.,LRCCP | Mousseau P.,OPERP GEPEA ERT 1086 | Bailleul J.L.,French National Center for Scientific Research | Deterre R.,OPERP GEPEA ERT 1086
Inverse Problems in Science and Engineering | Year: 2010

Thick rubber part moulding is a process, during which coupling between heat and chemical kinetic equations is strong. Automatic tooling control, therefore, is the guarantee of achieving proper curing within the mould. This article initially presents a detailed method for curing optimization. With this aim in view, the optimum temperature cycle for the desired curing state is examined. The use, here, of the conjugate gradient method implies to determine the solution of both adjoin and sensitivity equations. A sensitivity study is also conducted in order to improve the kinetic model. Finally, some optimization examples are discussed. © Taylor & Francis. Source

Rouillard F.,LRCCP | Heuillet P.,LRCCP | Omnes B.,CETIM
Constitutive Models for Rubber VIII - Proceedings of the 8th European Conference on Constitutive Models for Rubbers, ECCMR 2013 | Year: 2013

Rubber compounds exhibit non linear viscoelastic mechanical behavior, stress-strain response strongly depends on time and temperature parameters. For numerous applications and mainly for sealing applications, rubber parts often work under a given displacement. This type of loading, named stress relaxation, leads to a load decrease versus time due to viscoelastic effects. In case of sealing applications, contact pressure developed by a seal decreases and in extreme situations leaks occur in case of unsatisfactory design and/or non applicable material. This presentation deals with stress relaxation phenomena for sealing applications at low temperatures, for temperatures nearly or inferior to glass transition temperature (Tg) of the polymer(s) retained for the rubber compound. In this domain, between the rubbery state and the glassy state, the final behavior of the seal will depend on the whole loading history applied to the material combined with dilation phenomena given small strain variations of the material. © 2013 Taylor & Francis Group. Source

Discover hidden collaborations