Mechanical Response of T300/BMP350 Composites under Tensile Loading at Room and Elevated Temperatures

2014 ◽  
Vol 1035 ◽  
pp. 138-143
Author(s):  
Ping Zhou ◽  
Pu Rong Jia ◽  
Wen Ge Pan

In this paper, the effect of elevated temperature on the behavior of carbon fiber-reinforced T300/BMP350 unidirectional laminates was studied by loading static tensile on 0°, 90°and ±45° lay-up. The stress-strain relationships of the laminates under different temperatures were obtained. The effect of temperature on the mechanical properties of materials was systematically studied. The damage and failure mechanisms of the material were studied by analyzing the material stress-strain curves and the failure modes. Results show that the T300/BMP350 polyimide matrix composites have a strong resistance to high temperature. For 0° and 90° lay-up, the retentions of tensile strength and modulus are more than 80% and 50%, respectively. High temperature has little effect on the material failure modes. Finally, based on the test results, an empirical formula which relates strength and temperature of the material was fitted.

2016 ◽  
Vol 848 ◽  
pp. 174-178
Author(s):  
Qian Wang

In this paper, both the permittivity and the microwave transmittance properties of organosilicon-matrix composites under different temperatures have been studied. In order to investigate the reason for the changing of dielectric property, both TGA and high-temperature dielectric spectrum measurement have been carried out. A theoretical model of radome, with a temperature gradient distribution, has been built to analyze the dependence of microwave transmittance property on temperature. Based on the experimental results, we can optimize the effective operating temperature of this kind of organosilicone-matrix composites.


2021 ◽  
Author(s):  
Alireza Sayyidmousavi

Polymer matrix composites (PMC’s) are widely used in critical aerospace structures due to their numerous advantageous mechanical properties. Recently, PMC’s have been considered for high temperature applications where viscoelasticity arising from the time dependent nature of the polymer matrix becomes an important consideration. This inherent viscoelasticity can significantly influence deformation, strength and failure response of these materials under different loading modes and environmental factors. With a potentially large number of plies of different fiber directions and perhaps material properties, determining a fatigue failure criterion of any degree of generality through experiments only, may seem to be an unrealistic task. This difficult situation may be mitigated through the development of suitable theoretical micro or macro mechanical models that are founded on considering the fatigue failure of the constituting laminas. The micro‐approach provides a detailed examination of the individual failure modes in each of the constituent materials i.e. fiber, matrix. In this work, a micromechanical approach is used to study the role of viscoelasticity on the fatigue behavior of polymer matrix composites. In particular, the study examines the interaction of fatigue and creep in polymer matrix composites. The matrix phase is modeled as a vicoelastic material using Schapery’s single integral constitutive equation. Taking viscoelsticity into account allows the study of creep strain evolution during the fatigue loading. The fatigue failure criterion is expressed in terms of the fatigue failure functions of the constituent materials. The micromechanical model is also used to calculate these fatigue failure functions from the knowledge of the S‐N diagrams of the composite material in longitudinal, transverse and shear loadings thus eliminating the need for any further experimentation. Unlike the previous works, the present study can distinguish between the strain evolution due to fatigue and creep. The results can clearly show the contribution made by the effect of viscoelasticity to the total strain evolution during the fatigue life of the specimen. Although the effect of viscoelsticity is found to increase with temperature, its contribution to strain development during fatigue is compromised by the shorter life of the specimen when compared to lower temperatures.


2010 ◽  
Vol 2010 (HITEC) ◽  
pp. 000359-000366 ◽  
Author(s):  
Patrick McCluskey ◽  
Chandradip Patel ◽  
David Lemus

Elevated temperatures can significantly affect the performance and reliability of MEMS gyroscope sensors. A MEMS vibrating resonant gyroscope measures angular velocity via a displacement measurement which can be on the order on nanometers. High sensitivity to small changes in displacement causes the MEMS Gyroscope sensor to be strongly affected by changes in temperature which can affect the displacement of the sensor due to thermal expansion and thermomechanical stresses. Analyzing the effect of temperature on MEMS gyroscope sensor measurements is essential in mission critical high temperature applications, such as inertial tracking of the movement of a fire fighter in a smoke filled indoor environment where GPS tracking is not possible. In this paper, we will discuss the development of the high temperature package for the tracking application, including the characterization of the temperature effects on the performance of a MEMS gyroscope. Both stationary and rotary tests were performed at room and at elevated temperatures on 10 individual single axis MEMS gyroscope sensors.


2020 ◽  
Vol 54 (27) ◽  
pp. 4269-4282
Author(s):  
E Boissin ◽  
C Bois ◽  
J-C Wahl ◽  
T Palin-Luc

The mechanical response of polymer matrix composites exhibits a temperature dependency even if the service temperature range is lower than the glass transition temperature of the polymer matrix. This dependency is mainly due to the temperature effect on the mechanical behaviour of the polymer matrix. However, the micro- and meso-structures driving the composite anisotropy and local stress distribution play an essential role regarding the effect of temperature on damage mechanisms specific to reinforced polymers. There are few data in the literature on the sensitivity to temperature of damage mechanisms and scenarios of polymer matrix composites regardless of loading type. In this paper, after a synthetic literature review of the effect of temperature on polymers and polymer composites, several complementary tests are proposed to analyse the temperature effect on damage mechanisms undergone by laminated composites under in-plane quasi static loadings. These tests are applied to an acrylic-thermoplastic composite reinforced by glass fibres in its service temperature range of –20℃ to 60℃. The results show that the testing temperature has a significant impact on the mechanical response and damage mechanisms of the composite material in the selected temperature range, which is markedly lower than the glass transition temperature (around 100℃). While the temperature rise generates a gradual decrease in matrix stiffness and strength, the increase in matrix ductility associated to the stress heterogeneity in the composite microstructure produces a rise in the transverse cracking threshold and removes this damage mode during quasi-static tensile tests when the temperature shifts from 15℃ to 40℃.


Author(s):  
Pradeep Lall ◽  
Geeta Limaye

Current trends in the automotive industry warrant a variety of electronics for improved control, safety, efficiency and entertainment. Many of these electronic systems like engine control units, variable valve sensor, crankshaft-camshaft sensors are located under-hood. Electronics installed in under-hood applications are subjected simultaneously to mechanical vibrations and thermal loads. Typical failure modes caused by vibration induced high cycle fatigue include solder fatigue, copper trace or lead fracture. The solder interconnects accrue damage much faster when vibrated at elevated temperatures. Industry migration to lead-free solders has resulted in a proliferation of a wide variety of solder alloy compositions. Presently, the literature on mechanical behavior of lead-free alloys under simultaneous harsh environment of high-temperature vibration is sparse. In this paper, the reduction in stiffness of the PCB with temperature has been demonstrated by measuring the shift in natural frequencies. The test vehicle consisting of a variety of lead-free SAC305 daisy chain components including BGA, QFP, SOP and TSOPs has been tested to failure by subjecting it to two elevated temperatures and harmonic vibrations at the corresponding first natural frequency. The test matrix includes three test temperatures of 25C, 75C and 125C and simple harmonic vibration amplitude of 10G which are values typical in automotive testing. PCB deflection has been shown to increase with increase in temperature. The full field strain has been extracted using high speed cameras operating at 100,000 fps in conjunction with digital image correlation. Material properties of the PCB at test temperatures have been measured using tensile tests and dynamic mechanical analysis. FE simulation using global-local finite element models is thus correlated with the system characteristics such as modal shapes, natural frequencies and displacement amplitudes for every temperature. The solder level stresses have been extracted from the sub-models. Stress amplitude versus cycles to failure curves are obtained at all the three test temperatures. A comparison of failure modes for different surface mount packages at elevated test temperatures and vibration has been presented in this study.


2005 ◽  
Vol 127 (4) ◽  
pp. 446-451 ◽  
Author(s):  
Ming-Hwa R. Jen ◽  
Lee-Cheng Liu ◽  
Jenq-Dah Wu

The work is aimed to investigate the mechanical responses of bare dies of the combination of pure tin∕Al–NiV–Cu Under bump metallization (UBM) and packages of pure tin∕Al–NiV–Cu UBM/substrate of standard thickness of aurum. The mechanical properties under multiple reflow and long term high temperature storage test (HTST) tests at different temperatures and the operational life were obtained. A scanning electron microscope was used to observe the growth of IMC and the failure modes in order to realize their reaction and connection. From the empirical results of bare dies, the delamination between IMC and die was observed due to the tests at 260 °C multiple reflow. However, their mechanical properties were not affected. Nevertheless, the bump shear strength of bare dies were decreased by HTST tests. In package, all the results of mechanical properties by multiple reflow test and HTST test were significantly lowered. It was shown that the adhesion between bump and die reduced obviously as tests going on. As for high temperature operational life test in the conditions of 150 °C and 320 mA (5040A∕cm2), the average stable service time of the package was 892 h, and the average ultimate service time of the package was 1053 h.


2019 ◽  
pp. 14-19
Author(s):  
O. N. Budadin ◽  
W. Yu. Kutyurin ◽  
A. N. Rykov ◽  
P. I. Gnusin

The main task of the contribution was the estimation of the possibility of using Fiber Bragg Gratings as a mean of measuring the deformation in standard carbon fiber samples at elevated temperatures. The article presents the results of experiments on the measurement of deformations in a carbon sample using Fiber Bragg Gratings on an optical fiber. Deformations were measured in the process of stretching the sample at different temperatures (range from 20 to 140 °C). It is shown that FBGs integrated into the sample material give more stable, reproducible readings, unlike to inlay on the outer surface. It has been established that the use of several FBGs with different sensitivity to temperature or deformation (created by mechanically decoupling the sensor from the sample) makes it possible to compensate the effect of temperature when measuring deformations. The quantitative results of measurements are provided.


2014 ◽  
Vol 1018 ◽  
pp. 31-38
Author(s):  
Edgars Locmelis

Ultrasonic non-contact handling is used to manipulate surface sensitive and fragile workpieces, e.g. wafers and glass plates, without mechanical contact. While the technology is available forapplications at room temperature, some of the manufacturing processes of products mentioned aboverequire handling at elevated temperatures. To enable this technology for handling in thermal processesan ultrasonic system for increased working temperatures is required. In order to adapt the ultrasonicsystem to the limited working temperature of the actuator, the handling system has to be operated attwo different temperatures. Due to the small change of the Young's modulus over temperature, quartzglass was chosen as material for the components in the high temperature region. The paper presentsthe design and manufacturing of a novel ultrasonic system operated at 790 °C while the actuator iskept at room temperature.


2012 ◽  
Vol 246-247 ◽  
pp. 3-6
Author(s):  
Xiu Ying Yang ◽  
Qiang Qin ◽  
Yang Yang Cui

To study the performance of steel at elevated temperatures, the stress and deformation of steel beam were analyzed under high temperature in this paper. During the analysis, the properties of steel material must be defined firstly, which are the decisive factor affecting the carrying capacity of steel beam. The mechanical and physical properties of steel at high temperatures were accessed accordance to the provisions of the European specification in analysis. The finite element program ANSYS was used to analyze the constraints steel beam, which subjected to the uniformly line loads, then the steel beam was heated up continuously, and the mechanical properties and deformation of the steel beam was analyzed at different temperatures. The regularity of mid-span deflection changing with temperature was concluded, so as the variation of axial stress at both ends of the steel beam.


2016 ◽  
Vol 51 (18) ◽  
pp. 2619-2629 ◽  
Author(s):  
Junbo Xie ◽  
Guodong Fang ◽  
Zhen Chen ◽  
Jun Liang

Tensile experiments of three-dimensional needled C/C-SiC composite from room temperature to 1800℃ were performed to investigate tensile behavior. The damage characteristics and macroscopic mechanical behavior of the composite are relevant to the testing temperature and off-axis angles of the tensile loading. The tensile strength increased while the modulus decreased with the increase of temperature. A high-temperature nonlinear constitutive model was established to analyze the nonlinear stress–strain relationship of the composite. Plastic strain accumulation and stiffness degeneration were described by the plasticity and damage theories. The effect of temperature on the tensile behavior of the composite was particularly considered in this model by introducing a thermal damage variable. The proposed constitutive model can predict the stress–strain behavior of the material subjected to different off-axis tensile load, and at different temperatures. Fairly good agreement was achieved between the predicted and experimental results.


Sign in / Sign up

Export Citation Format

Share Document