Recent Advances on the Mechanical Behaviour of Materials

Frequently, buildings in urban areas are designed by considering the response of structures as stand-alone i.e., a single structure, with no neighbouring structures. Nevertheless, the existence of a high density of buildings in large metropolitan areas inevitably results in the likelihood of seismic interaction of adjacent buildings through the underlying soil. This problem is better known as Structure-Soil-Structure Interaction (SSSI), and this interaction can either increase or decrease the seismic response of a structure, and its relevance was highlighted in early studies (Lee and Wesley in Nucl Eng Des 24:374–387, [1]; Kobori et al. Dynamical cross-interaction between two foundation, [2]; Wong and Luco in Soil Dyn Earthq Eng 5:149–158, [3]; Triantafyllidis and Prange in Soil Dyn Earthq Eng 7:40–52, [4]). In this research, we explore the influence of Structure-Soil-Structure Interaction (SSSI) between a pair of cross-laminated timber (CLT) buildings under seismic excitation. A complete 3-dimensional high-order model of the soil and buildings is performed. The finite element method is used for the numerical simulations in ANSYS. The interaction effects are investigated for different heights of the buildings and soil properties. Results suggest that the SSSI can affect displacement, inter-story drift and accelerations. The impact of the SSSI effects is more relevant for loose soil.

Most non-stochastic architected materials proposed to date have been based on periodic structures with a homogeneous topology and uniform materiality. Topologically and materially heterogeneous mechanical metamaterials promise novel capabilities, expanding the design space through growth in degrees of freedom. However, this leads to increased design complexity, as the space of possible solutions becomes a high-dimensional domain. We present a computational design automation framework for novel heterogeneous mechanical meta-material designs with a CMA-ES black-box evolutionary algorithm at its core, and demonstrate its application through a case study on new 2D pentamode meta-materials. Pentamodes are defined by extreme values of the bulk-to-shear modulus ratio (B/G) and are of particular interest due to both their unusual properties, being very stiff under compression yet easy to deform in shear, and potential as building blocks for the realization of any physically possible and desired elastic property. For the pentamode case study, this approach resulted in irregular composite structures with large B/G ratios, many structures having values between 1–3 × 10⁴, a range well above previously reported experimental values of 10³. The new meta-material systems it generated do not present the point-like connections of the classic pentamode diamond-type lattice, which is a key practical limitation for application. This work shows that population-based metaheuristic computational methods can reliably generate novel mechanical metamaterial designs capable of achieving more extreme performance than more traditional metamaterial design approaches.

The Edinburgh model (Brown et al. in Granular Matter 16:299–311, [1]) as an addition of the discrete element method allows to define a tool to simulate cohesive granular materials due to its capacity to represent, in case of concrete, the coarse aggregate as particles and the cementitious matrix as bond between elements. The Edinburgh Bonded Particle Model (EBPM) defines its operation through two different contact models, the theory of the Timoshenko Beam Bonded Model (TBBM) when particles are bonded, and the Hertz-Mindlin Contact Model (HMCM) when the connection between elements is broken. The purpose of this work is to computationally represent different structures of civil engineering (Molina, Tavarez and Plesha in Int J Numer Meth Eng 70:379–404, [2]) through the Edinburgh Bonded Particle Model and analyze their behavior. These models represent basic civil engineer structures with the purpose of comparing their behavior with real documented results. Two classical models are studied, a dam with distributed hydrostatic force at three different water levels and a cantilever beam with the application of a dynamic force. The result of the simulation is the behavior of two concrete structures, and through different parameters like forces, displacement of the particles and their bonds is possible to represent the deformation and cracking of the material by analyze the results in different timesteps. This method is capable of adequately represent the elastic and inelastic behavior of concrete during loading process, and its open a gap to continuing researching about the method and its applications in civil engineering.

Auxetic materials have recently attracted particular interest due to their wide range of functional applications, especially in smart devices and implants. Characterized by a negative Poisson’s ratio, auxetic materials subjected to tension expand in the transverse direction of the load, while if subjected to compression, undergo shortening in the direction transverse to the load. This study presents the identification and analysis of a material finite element model capable of simulating the behavior of auxetic structures. A uniform pattern of auxetic cells formed by “reentrant bars” constitutes the macromaterial with adjustable mechanical properties according to the angle of the struts. The auxetic structure is first investigated in compression and then impregnated with an epoxy resin to achieve higher levels of energy absorption capacity. By comparing the numerical results obtained with the available experimental data, the challenges and a strategic roadmap to achieve accurate prediction of the mechanical behavior of resin-filled auxetic material are established.

Bone remodeling and bone resorption are two of the most important processes during bone healing. There have been numerous experiments to understand the effects of mechanical loading on bone tissue. However, the progress is not much due to the complexity of the process. Although it is well accepted that bone is consisting of two phases, such as a solid and a fluid part, all experiments consider only the solid part for simplicity. Recent studies demonstrated that despite the induced strain field inside the solid part due to mechanical force, the fluid part plays a crucial role in the bone remodeling process as well. The interstitial fluid is pressed through the osteocyte canaliculi and produces a shear stress field that excites osteocytes to produce signaling molecules. These signals initiate the bone remodeling process within the bone. In addition, the strain field of the solid part stimulates osteoclast and osteoblast cells to commence bone resorption and apposition, respectively. A combination of these two processes could be the exact bone regeneration process. The purpose of this investigation is to examine the influence of the fluid stream inside the bone. Using theory of porous media, we considered the bone as a bi-phasic mixture consisting of a fluid and a solid part. Each constituent at a given spatial point has its own motion. Also, we assumed that this bi-phasic system is closed with respect to mass transfer but open with respect to the momentum. Furthermore, the characteristic time of chemical reactions is assumed several orders of magnitude greater than the characteristic time associated with the prefusion of the fluid flow, so the system is considered isothermal. We derived the balance of linear momentum for each constituent concerning these assumptions, resulting in coupled PDEs. Furthermore, the advection term is considered for the fluid part movement. The Finite Element Method (FEM) and the Finite Volume Method (FVM) are used to solve the balance of linear momentum for the solid and fluid parts, respectively. Finally, the results are compared with the theory of poroelasticity.

The buckling collapse induced by external pressure is the main failure mechanism in thermoplastic liners for oil applications. This phenomenon is caused by permeation of dissolved gases in oil through the polymer pipe thickness. This results in gas trapped into the annular cavity defined by the metallic host pipe and the external liner surface. During operation, the pressures of the annular and inner cavities remain in equilibrium. The problem may arise when depressurizing the pipeline, due to the resulting pressure difference between both cavities. If the liner structure is not capable to bear the radial load, collapse buckling occurs. The damage grade depends on many factors that can be divided in two main aspects: (i) the liner resistance, related with its geometry, boundary conditions and material behavior; (ii) and the actual loading case as a consequence of the compressible fluid in the annulus between liner and host pipe. Although both must be properly determined to predict structure behavior, works on this subject are often concerned only with liner resistance. In this work, we propose a simple experimental method to quantify the annular resulting space after liner fitting. This information is then used to estimate the actual loading case. Finally, by using previously verified numerical methods to predict the liner resistance, we establish safe operation parameters in order to prevent buckling collapse.

This paper explores the application of additive manufacturing (AM) technology, specifically 3D printed concrete, in the mining industry using tailings as a sustainable alternative to fine aggregate. AM offers benefits such as reduced waste, shorter construction times, and lower costs. By incorporating tailings in 3D printed concrete, environmental challenges associated with tailings disposal can be mitigated, while promoting resource efficiency. The study reviews the current state of AM technology and its implications for mining. Tailings, the waste fraction of mined materials, can be effectively utilized in concrete production. Various studies have shown that tailings can achieve comparable mechanical properties to conventional concrete with appropriate adjustments to the mixture. The inclusion of tailings in 3D printed concrete presents environmental advantages, reducing waste and greenhouse gas emissions associated with traditional concrete production. However, further research is needed to optimize the printing process, mixture compositions, and establish industry standards. A brief study on the chemical components present in copper tailings shows that is feasible to use tailings as replacement of aggregates and even a portion of cement, as it has similar components. Aswell as being safe to use with admixtures as there is not any chemical or mineral that may react when applied. By embracing AM technology and incorporating tailings, the mining industry can achieve environmental benefits, resource optimization, and promote sustainability. Continued advancements in AM technology will pave the way for the widespread adoption of 3D printed concrete with tailings, pushing the mining sector and contributing to a more sustainable future.

Headed connectors are a promising alternative for anchoring elements of reinforced concrete structures, replacing hooks, curves and straight bars, which in situations of geometric limitation, such as in the beam-column connection, may restrict the necessary embedding of the anchors, which is not a problem with the headed connector. However, this application is not trivial, and the knowledge of rupture mechanisms and tensile strength of anchorage in reinforced concrete elements needs advances, mainly in the computational field. So, the critical point of this application is to know the parameters that influence the pull-out resistance of anchorages under tension. In this sense, this work aimed to develop 3D models of finite elements to simulate the tensile strength of connectors with headers embedded in reinforced concrete under edge and group effects. For this, computational simulations were produced with the Abaqus software, applying a dynamic analysis explicitly, to represent the pulling-out of the anchorages and the rupture of the concrete. With the calibrated numerical model, a parametric numerical study was developed to evaluate the influence of several factors on the anchorage resistance capacity. Load-slip values, reinforcement strain and failure modes were consistent with experimental tests. Therefore, the proposed numerical model accurately predicted the mechanical pull-out behaviour of the headed connector embedded in concrete elements.

In this paper, the influence of strain rate on the compressive response of concrete specimens is investigated by means of Smoothed Particle Hydrodynamics simulations. The material response is described by the RHT model, which combines three independent strength surfaces with a non-linear equation of state for shock waves. Concrete cubes made of normal strength of 35 MPa are subjected to uniaxial compression loads at different strain rates. In particular, high strain rate effects are assessed on the shape of load–displacement curves, maximum compressive strength, and damage pattern. The present work provides further insight into the complex mechanisms of compressive failure behaviour of concrete materials under high strain rates, with potential applications to the future design of more resilient structures when subjected to earthquake and blast loading cases.

Taking inspiration from biological structures that have developed over millennia provides a unique approach to identifying innovative solutions to engineering problems. Alligator mandible structures exhibit high strength properties under their natural loading conditions that result in their evolved shape. The morphological variables of alligator mandibles have been compared from evolutionary perspectives through simplified beam models and the finite element method (FEM). However, a comparison of the 3-dimensional structural features is yet to be explored from an engineering perspective. This study presents the biomechanical analysis of an alligator mandible structure under cantilever loading conditions using FEM. The initial, solid geometry of the structure is compared to hollow models with varied shell thickness to analyse its effect on the structural stiffness under bending and compressive loading conditions. The outcome of these results demonstrates the functional principles of the mandible that can be applied to structural engineering applications. These principles can additionally be used as a baseline for the design of novel, more optimised structures under similar load cases.

Traditional Large Power Transformer (LPT) tanks have been typically designed with a rectangular geometry. The variation in LPT tank geometry to accommodate a completely different geometry for LPTs has not been considered much in research and literature. This preliminary work presents an initial analysis of two LPT tank geometries: the common one, and the proposed one using pressure vessel theory and finite element analysis methods. Further, apart from the effect of geometry on the mechanical reliability of LPT tanks, this study investigates the effect of a change in the tank’s material from traditional low-carbon steel (LCS) to Polymer Matrix Composites (PMCs). The result shows that a capsular type of tank geometry made with Carbon Fiber Reinforced Polymer (CFRP) material potentially offers superior resistance to internal pressure loading 10 times higher than the tank with a rectangular geometry made with LCS material. The design limit for an LPT’s internal pressure is about 0.2 MPa, and this capsular design is shown to accommodate 10 times this pressure limit. The outcome of this study, therefore, proposes a new geometry for further investigation for application in LPT tanks.

Soft stories are a common reason for building collapses during severe earthquakes. This paper investigates a solution for seismic rehabilitation with hysteretic dampers for a building in Spain affected by the Lorca earthquake in 2011. The building had reinforced concrete frames, stronger beams than columns, a soft first story, and masonry walls. The dimensions of hysteretic dampers are presented in terms of their mechanical properties as stiffness, strength, and yield deformation. The energy-based method provides the stiffness, strength, and energy dissipation capacity required by hysteretic dampers to get the entire structure to endure the design earthquake without exceeding the maximum imposed drift on the first story. The seismic performance of the upgraded structure is evaluated by nonlinear dynamic analyses, considering the energy that contributes to structural damage expressed in terms of equivalent velocity based on the Seismic Standard NCSE-02, the accelerograms of the Lorca earthquake, and 23 historic earthquakes scaled to the energy input. In conclusion, the solution improves seismic performance. Hysteretic dampers increase the stiffness of the soft story and take it to similar levels to the upper stories. The modes of vibration are translational, the drift of the first story decreases by 50%, and drifts of the upper stories are kept low. The damage is concentrated on the hysteretic dampers instead of the main structure, and plastic joints are concentrated on the base of the first-story columns, which is an acceptable mechanism to dissipate energy to avoid the main structure collapse.

This paper examines the potential use of tailings as a partial replacement for fine aggregate in shotcrete applications within the mining industry. The study explores the environmental, performance, and economic advantages and challenges associated with incorporating tailings into shotcrete mixtures. The research findings reveal that shotcrete mixtures containing tailings can achieve comparable or even superior compressive and flexural strength properties compared to conventional shotcrete, both in early age and at 28 days. Moreover, utilizing tailings in shotcrete offers environmental benefits by reducing waste accumulation and minimizing the need for transporting and maintaining tailings storage facilities. This not only mitigates environmental contamination but also reduces fuel consumption and associated greenhouse gas emissions. However, the successful implementation of shotcrete with tailings requires addressing technical and operational challenges. Factors such as porosity, temperature, and pumping control significantly impact shotcrete quality and homogeneity, necessitating the use of inorganic additives, appropriate curing measures, and fiber reinforcement to enhance compaction and reduce porosity. Furthermore, it is noteworthy that the Chilean shotcrete regulations share similarities with international standards such as ACI and EFNARC, ensuring the applicability and quality of shotcrete mixtures with tailings within the Chilean mining context. Concluding the integration of tailings in shotcrete presents an opportunity to improve sustainability and efficiency in the mining industry. Proper tailings selection, pre-treatment, and adherence to standards are crucial for successful implementation.

The high environmental impact of the cement industry demands the study of new cementitious materials. Often supplementary cementitious materials such as fly ash or silica fume are used; however, the depletion of raw materials encourages the assessment of new sources. Due to the high calcium content of snail shells, this research explored the use of crushed powder of Helix Aspersa to replace cement, evaluating its use at different percentages of replacement in weight (0, 5, and 10%), calcination temperature (0, 450, and 900 °C) and water-cementitious materials ratios (0.35, 0.40, and 0.45). The results included analysing setting time, compressive and flexural strength, water absorption, and shrinkage. Results indicated that snail shells (i) create an expansion during the first days (~15%), reaching similar values at 28 days, (ii) decrease the water absorption at calcination temperatures ≥450 °C, and (iii) slightly reduce the flexural strength (~16% in average) and compressive strength (~10% in average). As the main decrement of the responses is at a low w/cm ratio, it is expected that calcined snail shells offer the opportunity to save cement and pollution from the construction industry.

The experimental results obtained in the laboratory are presented, where under controlled semi-autogenous grinding (SAG) conditions, a single-size siliceous ore material was ground (12.5 mm > d100 > 9.5 mm) to which a pulp prepared from the same material with different fine concentrations below 200 mesh (d100 = 75 um), this being considered a polluting phase. The aim of the research is to determine the influence on the fracture kinetics of coarse particles under the premise that the presence of fines in a pulp modifies the rheological behavior of an initially Newtonian-type fluid such as water to a non-Newtonian one, as has been showing the mineral pulps. Initially, and due to the requirement of knowing the rheological response of the polluting pulp, 7 samples were formulated. The apparent viscosity values were obtained from tests carried out considering a shear rate of 22 s⁻¹. The results obtained show an inversely proportional relationship between the presence of fines and the specific fracture rates of the coarse particles.

Lightweight concrete has as its main advantage the possibility of reducing structures’ weight. In addition, the fact that they have a better-quality transition zone compared to traditional concrete makes these concretes an alternative to improve the durability of structures. Lightweight concrete is essentially made up of binder, aggregates, and water. Several studies have already shown that the granulometry of the aggregate and the water-cement ratio directly affects the strength of concrete. Thus, the objective of this work was to evaluate the influence of granulometry, water-cement ratio, and proportion of aggregates on tensile strength, compressive strength, and modulus of elasticity of lightweight concrete produced using Brazilian expanded clay. For all evaluated concretes, the same cement consumption was used, and the Reference curve method (Faury method) was used to find the best proportion between the solid materials in the mixture. The mechanical properties of tension and compression were evaluated through destructive tests, and the modulus of elasticity was obtained through non-destructive tests. The results showed that for the same cement consumption, the reduction of water consumption and the proportion of lightweight aggregates in the composition contribute to the improvement of the mechanical properties of the evaluated concretes, However, they reduce the workability and favor the gain of specific mass.

As reported in literature, accelerated corrosion process using impressed current technique is widely adopted to corrode the rebar in reinforced concrete specimens in order to characterise the mechanical properties and to study the response of the corroded structure. Often variations are observed between the actual mass loss achieved during accelerated corrosion process and the target mass loss estimated using Faraday’s law. In this paper, an effort has been made to quantify the variations, in terms of calibration factors for the reinforced concrete prism specimens. Three cases viz., Case 1 passing the current through longitudinal rebar by allowing the current to pass through transverse reinforcement, Case 2 passing the current through the longitudinal rebar by insulating the transverse rebar connection and Case 3 passing the current through longitudinal as well as transverse rebar separately by insulating the connection between rebars. Calibration factors for longitudinal and transverse rebars are obtained for the three cases considered. Further, the yield strength (fy), ultimate tensile strength (fu), and elongation (\({\delta }_{c})\) of the corroded rebars of the specimens investigated are obtained. The constants for fy, fu, \({\delta }_{c}\), called here as \({\alpha }_{1}{,\alpha }_{2,}{\alpha }_{3}\), respectively, are estimated in the present study and comparisons have been made with values obtained from existing models in literature.

One of the technological challenges in manufacturing components in polymeric composite materials reinforced with carbon fibers is the occurrence of delamination during the drilling process of the parts. Drilling of composite material is a widely used process in the energy, aviation, and automobilist industries since most pieces are assembled by riveting or screwing, and delamination is the factor with the most significant rejection in terms of hole quality, accounting for 60% of all parts rejected due to non-compliance issues. This study aims to find the influence of cutting speed and feed rate in the occurrence of defects in the drilling of the thermoplastic matrix composite of polyamide 6 reinforced with carbon fibers. Two different tools were used: a carbide twist drill and another diamond-coated twist tool. A full factorial matrix was used with cutting speed (40.90, 90.01, and 113.12 m/min) and three feed levels (0.018, 0.050, and 0.081 mm/rev). Machining potency, thrust force, and vibration were acquired during the drilling process, analyzed, and correlated with the hole delamination factor. The delamination behavior on the hole’s entrance and exit are different and affected differently by cutting parameters, which push-out delamination on the hole’s exit has been more critical. The found parameters to reduce delamination are V_c = 40.90 m/min, f = 0.081 mm/rev, and PCD-coated carbide tool, which indicates that thermal damage is more prominent than mechanical damage. Machining potency and thrust force correlate with the delamination factor, meaning potential signals for monitoring delamination in the PA6-based carbon-reinforced composite drilling process.

Recently, there has been a growing interest in the development of adaptive wing structures for aerospace purposes. One promising approach involves utilizing carbon fiber-reinforced elastomeric skins, enabling them to undergo one-dimensional (1D) morphing. This paper presents a comprehensive investigation into the synthesis, characterization, and void analysis of a specifically designed elastomer-based skin for carbon fiber-reinforced 1D morphing wings. The chosen elastomeric material, based on silicon, possesses desirable mechanical properties such as high flexibility and durability. The synthesis process involves precisely formulating the elastomer and employing a meticulous fabrication technique to achieve a uniform and well-adhered skin onto the unidirectional carbon fiber. Micro-ct tomography, a non-destructive imaging technique, was utilized to assess the quality of the carbon fiber reinforcement and examine any potential voids or defects. The results from the X-ray tomography analysis provide valuable insights into the distribution and morphology of voids within the carbon fiber, both before and after cyclic stretching. By quantifying the void content and analyzing their distribution patterns, it is determined that the 1D-reinforced skin exhibits excellent structural integrity and quality. In summary, a silicon-based morphing skin, reinforced with unidirectional carbon fiber, is successfully synthesized. The 3-dimensional X-ray tomography analysis reveals a void content of 0.32% after synthesis, which slightly increases to 0.73% after ten cycles of loading-unloading test-a level that is deemed acceptable. Furthermore, this arrangement enables 1D morphing of up to a maximum of 200% with ease. The findings of this study contribute to the advancement of elastomeric materials for morphing skins in aerospace applications.

This study examines the utilization of pumice aggregate in lightweight concrete as a means to reduce the high self-weight associated with conventional concrete. The excessive self-weight of traditional concrete poses economic and structural challenges, making it less favourable in certain applications. In order to mitigate dead loads and improve thermal insulation, lightweight concrete with reduced density is employed, achieved through the partial replacement of coarse aggregate with pumice. The research focuses on comparing conventional concrete to lightweight aggregate concrete on the mix ratio of M30 with the addition of poly carboxyl ether. Various percentages of pumice replacement, ranging from 20 to 100%, are investigated. The objective of this investigation is to identify the most effective replacement alternative by evaluating the split tensile and compression strength properties of lightweight aggregate concrete, and subsequently comparing them to those of conventional concrete.

Concrete is a versatile and resilient construction material widely used in various applications. The incorporation of silica particles, particularly Nano silica, has emerged as a promising approach to reduce cement consumption and enhance the performance of concrete. Nano silica, a type of Nano material, has the ability to modify the molecular structure of concrete, thereby improving its bulk properties and mechanical behaviour. Through its Pozzolanic nature, Nano silica reacts with free lime during cement hydration, results in the development of additional C-S-H gel, which enhances the concrete’s impermeability, strength, and durability. This experimental study focused on incorporating Nano silica into M30 Grade concrete at various concentrations (0, 0.5, 1, 1.5, and 2%). The results clearly demonstrate that Nano silica-based concrete exhibits significantly higher strength compared to traditional concrete. These findings highlight the potential and promise of Nano silica-based concrete in advancing concrete technology.

Fatigue failure in components subjected to variable loads is a common issue in engineering, necessitating the optimization of characterization techniques. The assessment of the fatigue limit of the materials involved is crucial in the high-cycle fatigue regime. However, determining this limit requires executing numerous demanding and time-consuming tests, which can be costly. Consequently, there is growing interest in developing alternative methods that provide faster and more efficient estimations. Among these methods, thermal approaches based on temperature changes occurring in materials under variable loads have gained significant attention, particularly with the advent of infrared thermography (IRT). IRT-based methodologies offer a notable advantage over conventional methods by enabling the estimation of fatigue limits at higher speeds. This advantage is particularly beneficial for components manufactured through additive manufacturing, where optimizing build parameters is essential. Furthermore, the thermoelastic effect enables thermoelastic signals to provide valuable insights into crack tip location and the estimation of fracture mechanics parameters. The combined utilization of IRT and digital image correlation (DIC) also offers a powerful approach for characterizing functional fatigue and obtaining comprehensive insights into phase transformations in functional materials. This synergistic combination allows for the acquisition of detailed information and enables more efficient characterization of functional fatigue. This study explores various applications of IRT for characterizing functional and structural fatigue in different materials. Additionally, it investigates thermographic estimation methods for determining fatigue crack tips in CT specimens. The study analyzes the applications of IRT both independently and in combination with other non-contact techniques.

This geotechnical report offers an exhaustive analysis of the geotechnical solution implemented for the foundation bases of the 7 towers of the Villa Panamericana complex. These towers, made up of three 19-story towers and four 20-story towers, were built as part of the 2019 Pan American Games project, in the Villa el Salvador district of Lima, Peru. It should be noted that this project presents structural challenges of an unprecedented magnitude in land of this type in the country, due to the characteristics of the soils of wind origin. To carry out the analysis, an investigative collaboration was carried out between several companies specialized in geotechnics. Various field exploration techniques were used to obtain precise information on the characteristics and behavior of the terrain. The results indicate the presence of granular soils of the clean sand type, poorly graded, slightly humid and with very little amount of fines, whose consistency, of these transported deposits, varies from loose on the surface, to moderately dense and dense at greater depths. Without the presence of groundwater levels. Different alternatives were evaluated to solve the problems in the support base, and finally it was decided to replace the soil with layers of hydraulic concrete at a depth of 3 m and superimpose a foundation plate. This innovative solution was chosen due to the magnitude of the structure, time constraints and the characteristics of the soil present.

The geotechnical analysis focused on evaluating the stability and safety of the remodeling of the TQ545 and TQ295 tanks at the Talara refinery, located in Piura, on the north coast of Peru. These tanks, with more than 70 years of operation, need to be updated in terms of compliance with current environmental and operational standards, to ensure their correct operation. The surrounding area is characterized by the predominant presence of granular soils, specifically silty sands (SM), with groundwater levels ranging from 0.80 m to 1.40 m in general. Since the location is in a subduction zone, at the convergence of the Nazca and South American tectonic plates, seismic movements are likely to occur. Due to this, the importance of identifying the strata susceptible to possible liquefaction problems is recognized. A geotechnical study campaign was carried out in the area to characterize the subsoil, evaluate its load capacity and differential settlements, and also determine the depth of the strata susceptible to liquefaction. Based on the results obtained, a geotechnical solution is proposed to improve the soil to a depth of 4 m, an area susceptible to liquefying, which consists of the construction of a causeway as a foundation base, which will reach superficial levels of the natural terrain, and superimposed will continue a 2-m-high embankment that will serve as support for the foundation rings, ensuring the stability and safety of the new tank structures.

To get better the fatigue life of mechanical system such as automobile, parametric Accelerated Life Testing (ALT) as new organized reliability method proposes to evaluate the design of mechanical systems subjected to repeated loads, based on failure mechanism and design. It covers: (1) parametric ALT scheme based on product BX life, (2) load investigation for ALT, (3) a tailored sample of ALTs with the modifications, and (4) a judge of whether the product design(s) attains the objective BX life. So, we suggest a generalized life-stress failure model with a new effort concept, accelerated factor (AF), and sample size with AF. This new parametric ALT might help engineer detect the design flaws of the mechanical product influencing reliability during the design phase. As the inappropriate design parameters are identified by experiment, the mechanical product should improve in reliability as measured by the increase in lifetime, L_B, and the lowering in failure rate, λ. As a result, companies can avoid recalls due to the field failures. As a test case, two cases were studied: (1) reciprocating compressors of French-door refrigerators failed from the marketplace and (2) the redesign of hinge kit system (HKS) in a domestic refrigerator. After a tailored of parametric ALT, the mechanical products such as domestic compressor and HKS with corrective action plans were anticipated to fulfill the life target—B1 life 10 years.