Structural efficiency of varying-thickness regolith-based lunar arches against inertial loading

Author(s):  
N. Kalapodis ◽  
C. Málaga-Chuquitaype ◽  
G. Kampas
BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 7079-7099
Author(s):  
Jianying Chen ◽  
Guojing He ◽  
Xiaodong (Alice) Wang ◽  
Jiejun Wang ◽  
Jin Yi ◽  
...  

Timber-concrete composite beams are a new type of structural element that is environmentally friendly. The structural efficiency of this kind of beam highly depends on the stiffness of the interlayer connection. The structural efficiency of the composite was evaluated by experimental and theoretical investigations performed on the relative horizontal slip and vertical uplift along the interlayer between composite’s timber and concrete slab. Differential equations were established based on a theoretical analysis of combination effects of interlayer slip and vertical uplift, by using deformation theory of elastics. Subsequently, the differential equations were solved and the magnitude of uplift force at the interlayer was obtained. It was concluded that the theoretical calculations were in good agreement with the results of experimentation.


Author(s):  
V Kumar ◽  
SJ Singh ◽  
VH Saran ◽  
SP Harsha

The present paper investigates the free vibration analysis for functionally graded material plates of linearly varying thickness. A non-polynomial higher order shear deformation theory is used, which is based on inverse hyperbolic shape function for the tapered FGM plate. Three different types of material gradation laws, specifically: a power (P-FGM), exponential (E-FGM), and sigmoid law (S-FGM) are used to calculate the property variation in the thickness direction of FGM plate. The variational principle has been applied to derive the governing differential equation for the plates. Non-dimensional frequencies have been evaluated by considering the semi-analytical approach viz. Galerkin-Vlasov’s method. The accuracy of the preceding formulation has been validated through numerical examples consisting of constant thickness and tapered (variable thickness) plates. The findings obtained by this method are found to be in close agreement with the published results. Parametric studies are then explored for different geometric parameters like taper ratio and boundary conditions. It is deduced that the frequency parameter is maximum for S-FGM tapered plate as compared to E- and P-FGM tapered plate. Consequently, it is concluded that the S-FGM tapered plate is suitable for those engineering structures that are subjected to huge excitations to avoid resonance conditions. In addition, it is found that the taper ratio is significantly affected by the type of constraints on the edges of the tapered FGM plate. Some novel results for FGM plate with variable thickness are also computed that can be used as benchmark results for future reference.


Author(s):  
Kishore Khanna ◽  
Vinay Kumar Gupta ◽  
Neeraj Grover

The study is carried out to develop a mathematical model to analyze creep response of a varying thickness rotating disc made of anisotropic functionally graded 6061Al-SiCw.composite. The thickness and content of reinforcement (SiCw) in the disc are assumed to decrease radially according to power law. The yielding of disc material is according to Hill’s criterion and creeping as per threshold stress based law. The developed model is used to obtain the creep stresses and strain rates in the disc for various types of materials’ anisotropy. The stresses and strain rates are noticed to depend on the materials’ anisotropy. The study reveals that the presence of kind of anisotropy wherein the disc material exhibits lower yield strength toward the radial and tangential directions than the axial direction is beneficial in reducing the creep stresses and creep rates in the disc, in comparison to isotropic FGM disc. An anisotropic FG disc, which has highest and the lowest yield strengths, respectively, along the axial and radial directions shows superior creep response.


Author(s):  
Manu Gupta ◽  
Ankit Kumar ◽  
Ajendra Kumar ◽  
Robin ◽  
Anuj Kumar
Keyword(s):  

1937 ◽  
Vol 74 (8) ◽  
pp. 337-359 ◽  
Author(s):  
C. T. Trechmann

1. The coral-rock commences nearly everywhere with a basal bed of varying thickness containing a fauna of pre-Pleistocene aspect among which the genus Haliotis (absent from these coasts at the present day), Pleurotomaria, Meiocardia, etc., are noticeable. This faunule may have lived at a depth of 700–1,000 feet.2. The supposition that the southerly anticlines are a later uplift than the main portion of Barbados is supported by the absence of ravines, and the presence of post-coral-rock beds which occur as coastal veneers at low altitudes, and in greater thickness in the south-east corner near Whitehaven.3. The south-east part of the island from Consett Point to Ragged Point has probably extended further seawards in comparatively recent times ; the series of converging faults and dislocations in the cliff sections suggest that the thrusts from the west or south-west may have been resisted by this part of the island.4. The relative claims of fault-scarping or marine erosion in production of the rising terraces is discussed ; and new information regarding the thickness of the coral-rock at sea-level from a boring is detailed.5. The finding of a faunule with Pliocene or possibly Miocene affinities at the base of the coral-rock puts the Oceanic series further back, into the Miocene.


1992 ◽  
Vol 118 (11) ◽  
pp. 3016-3035 ◽  
Author(s):  
D. S. Ramachandra Murthy ◽  
A. G. Madhava Rao ◽  
P. Gandhi ◽  
P. K. Pant

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