scholarly journals Scientists Float a New Theory on the Medusae Fossae Formation

Eos ◽  
2020 ◽  
Vol 101 ◽  
Author(s):  
Nola Redd
Keyword(s):  
Lightweight Material ◽  
Volcanic Debris ◽  
Martian Ocean

Pumice-like rafts of lightweight material could have carried volcanic debris across an ancient Martian ocean to build one of the most puzzling features on the Red Planet.

Face Wrinkling and Core Strength in Sandwich Construction

1960 ◽  
Vol 64 (591) ◽  
pp. 164-167 ◽  
Author(s):  
S. Yusuff
Keyword(s):  
High Stress ◽  
Core Layer ◽  
High Strength ◽  
Bending Rigidity ◽  
Core Strength ◽  
Surface Smoothness ◽  
Lightweight Material ◽  
The Core ◽  
Sandwich Construction ◽  
Strength Material

The effect of initial waviness on the wrinkling of faces in sandwich construction is studied. Formulae are derived to determine the failing stress when the faces wrinkle due to failure of the core in tension, compression or shear. The importance of core strength requirements in maintaining surface smoothness is noted. A comparison of theory with experiments is made, and the agreement between the two is found to be reasonably good.A sandwich construction consists of two thin face layers of high-strength material and a thick core layer of lightweight material. The function of the core is twofold. Firstly, it increases the bending rigidity of the faces and second, it stabilises them so that they will not wrinkle until high stress is reached.

El Chichon volcanic debris in an Arctic tropopause fold

1984 ◽  
Vol 11 (5) ◽  
pp. 421-424 ◽  
Author(s):  
M. A. Shapiro ◽  
R. C. Schnell ◽  
F. P. Parungo ◽  
S. J. Oltmans ◽  
B. A. Bodhaine
Keyword(s):  
El Chichón ◽  
Volcanic Debris ◽  
El Chichon

New Evidence of an Ancient Martian Ocean From the Global Distribution of Valley Networks

2018 ◽  
Vol 123 (8) ◽  
pp. 2138-2150 ◽  
Author(s):  
Ngai-Ham Chan ◽  
J. Taylor Perron ◽  
Jerry X. Mitrovica ◽  
Natalya A. Gomez
Keyword(s):  
Global Distribution ◽  
Valley Networks ◽  
Martian Ocean ◽  
New Evidence

scholarly journals Physical and Mechanical Properties of Cemented Ash-Based Lightweight Building Materials with and without Pumice

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Neslihan Doğan-Sağlamtimur ◽  
Adnan Güven ◽  
Ahmet Bilgil
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Building Material ◽  
Building Materials ◽  
Physical And Mechanical Properties ◽  
Mixing Ratio ◽  
Lightweight Material ◽  
Important Input ◽  
Axial Compressive Strength ◽  
International Companies

Pumice, cements (CEM I- and CEM II-type), waste fly and bottom ashes (IFA, GBA, and BBA) supplied from international companies were used to produce lightweight building materials, and physical-mechanical properties of these materials were determined. Axial compressive strength (ACS) values were found above the standards of 4 and 8 MPa (Bims Concrete (BC) 40 and 80 kgf/cm2 class) for cemented (CEM I) pumice-based samples. On the contrary, the ACS values of the pumice-based cemented (CEM II) samples could not be reached to these standards. Best ACS results (compatible with BC80) from these cemented lightweight material samples produced with the ashes were found in 50% mixing ratio as 10.6, 13.2, and 20.5 MPa for BBA + CEM I, GBA + CEM II, and IFA + CEM I, respectively, and produced with pumice were found as 8.4 MPa (same value) for GBA + pumice + CEM II (in 25% mixing ratio), BBA + pumice + CEM I (in 100% mixing ratio), and pumice + IFA + CEM I (in 100% mixing ratio), respectively. According to the results, cemented ash-based lightweight building material produced with and without pumice could widely be used for constructive purposes. As a result of this study, an important input to the ecosystem has been provided using waste ashes, whose storage constitutes a problem.

Material Selection Decision-Making Method for Multi-material Lightweight Automotive Body Driven by Performance

2021 ◽  
pp. 146442072110556
Author(s):  
Dengfeng Wang ◽  
Shenhua Li
Keyword(s):  
Decision Making ◽  
Material Selection ◽  
The Body ◽  
Analytic Hierarchy ◽  
Weighting Method ◽  
Lightweight Material ◽  
Automotive Body ◽  
Selection Decision ◽  
Hierarchy Process ◽  
Selection Of

This work proposes a material selection decision-making method for multi-material lightweight body driven by performance to achieve that the right materials are used for the correct positions of the automotive body. The internal relationship between performance and mass, cross-sectional shape, wall thickness parameters, and material properties of a thin-walled structure is studied. The lightweight material indices driven by performance are then established. The lightweight material indices and material price are taken as the decision-making criteria for the material selection of automotive body components. A hybrid weighting method integrated with the analytic hierarchy process, fuzzy analytic hierarchy process, and quality function deployment is proposed. The difficulty of quantitatively evaluating the performance requirements of different components of the body is solved using the proposed weighting method combined with the numerical analytical results of the component performance under multiple operating conditions of the automotive body. Then, the weight of the decision-making criteria for material selection is calculated. Grey relational analysis is used to make multicriteria decision-making on a variety of candidate materials to select the best material for body components. After the lightweight material selection of the front longitudinal beam of the automotive body, the frontal collision safety performance of the body is effectively improved, and the mass of the front longitudinal beam is reduced by 45%. Material selection result of the front longitudinal beam indicates that the proposed material selection decision-making method can effectively achieve the fast material selection of components in different positions of the body.

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