Static Analysis Research Articles

Practical solutions for global buckling analysis in tall buildings: classic sandwich continuous model

Static stability analysis of global buckling and critical load ratio calculation are among the fundamental and most important parameters for structural analysis and design in numerous engineering applications across various fields. Particularly in the field of structural engineering, the critical load ratio is a parameter that determines the overall performance of tall buildings; however, due to the complexity of coupled differential equations with variable coefficients associated with different classical continuous models, its analysis has not been widespread, and only specific cases have been solved. This article utilizes the classic sandwich beam, widely studied in the literature, to propose an analytical solution and a generalized numerical solution to address the elastic buckling problem with applications in tall building stability analysis. The analytical solutions are applicable to uniform structures and consider point, uniform, and variable compression loads along their length that can be expressed through polynomial functions. The generalized numerical solution addresses the general case of structures with uniform or variable properties. Numerical applications and parametric analyses show excellent agreement between the results of the proposed methods and those of one-dimensional finite element methods. The influences of key parameters on the behavior of the eigenvalue associated with global buckling analysis are analyzed, and graphs and tables are proposed for direct practical application by engineers. Due to their mathematical formulation and excellent precision in results, the proposed methods can be safely used in the preliminary and final analysis of tall buildings and can be easily adapted to other engineering fields.

Development of an Underwater Adaptive Penetration System for In Situ Monitoring of Marine Engineering Geology.

In recent years, offshore wind farms have frequently encountered engineering geological disasters such as seabed liquefaction and scouring. Consequently, in situ monitoring has become essential for the safe siting, construction, and operation of these installations. Current technologies are hampered by limitations in single-parameter monitoring and insufficient probe-penetration depth, hindering comprehensive multi-parameter dynamic monitoring of seabed sediments. To address these challenges, we propose a foldable multi-sensor probe and establish an underwater adaptive continuous penetration system capable of concurrently measuring seabed elevation changes and sediment pore water pressure profiles. The reliability of the equipment design is confirmed through static analysis of the frame structure and sealed cabin. Furthermore, laboratory tests validate the stability and accuracy of the electrical and mechanical sensor measurements. Preliminary tests conducted in a harbor environment demonstrate the system's effectiveness.

Speeding up static analysis with the split operator

In the context of abstract interpretation-based static analysis, we propose a new abstract operator modeling the split of control flow paths: the goal of the operator is to enable a more efficient analysis when using abstract domains that are computationally expensive, having no negative effect on precision, and occasionally resulting in a more precise analysis. We focus on the case of conditional branches guarded by numeric linear constraints, including implicit numerical branches. We provide an experimental evaluation of real-world test cases, showing that by using the split operator we can achieve significant efficiency improvements with respect to the classical approach for a static analysis based on the domain of convex polyhedra. We also briefly discuss the applicability of this new operator to different, possibly non-numeric abstract domains.

Diagnosing electrostatic problems and hazards in industrial processes: Case studies

AbstractStatic electricity is a phenomenon commonly encountered yet often misunderstood and underestimated in terms of its hazard potential; it continues to challenge the safety and reliability of industrial processes, particularly those involving flammable substances. This paper delves into the critical issue of electrostatic hazards in industrial settings by presenting two flash fire/explosion case studies, one involving biphenyl dust and the other gasoline vapor; both linked to electrostatic discharges. The first case study examines an explosion in a flaker and pack‐out hopper during biphenyl flake manufacturing. The investigation reveals the role of electrostatic charges in the incident and how well‐intentioned equipment changes created warning signs of increased risk that were missed. The second case study discusses a gasoline vapor flash fire, highlighting the common yet overlooked hazard of static electricity during the transfer of flammable liquids. It underscores how common activities involving people can generate sufficient electrostatic charge to ignite flammable vapor–air mixtures in industry. The outcomes of these studies highlight the importance of acting on early warning signs of static electricity and the crucial role of data‐driven diagnostic techniques in addressing and controlling those hazards. By dissecting the intricacies of electrostatic phenomena, safety professionals can formulate actionable strategies to adapt plant operations and prevent hazards from static electricity. The paper advocates for a proactive approach to identifying and mitigating electrostatic risks in industrial settings beginning with process hazard analyses that incorporate static electricity hazards analysis and continues through employee training to ensure that early warning signs are identified, understood, and acted upon. It stresses the need for comprehensive safety measures, including proper grounding and bonding, use of static dissipative materials, and regular maintenance of safety equipment, to prevent incidents. Through these case studies, the paper contributes to understanding of electrostatic hazards in industrial processes and highlights the importance of integrating electrostatic safety measures into routine industrial operations.

Influence of strut angle and radius on the energy absorption and failure mechanisms in 3-strut, 4-strut and 6-strut lattice structures

Abstract 3D-printed truss structures have remarkable potential in the aerospace and weight-critical technologies fields. However, design parameters need to be carefully considered. A low overhang angle or diameter can result in discrepancies. This research presents an approach by examining the effect of strut overhang angle and radius on the mechanical properties of 3-, 4- and 6-strut lattice structures under compressive loading. 1.6- and 2.4-mm diameter struts were designed with 45°, 50°, 55° and 60° overhang angle strut lattices. Experiments were simulated and compared with test results for each parameter. Even if joint regions have little effect on specimens’ density, it has a remarkable effect on mechanical properties of the specimen. To simulate this, many studies were investigated to simulate joint regions. The study’s goal is to deepen the understanding of how design variations in strut lattice structures influence their energy-absorbing characteristic and mechanical behavior, using a combination of static tests and finite element analysis for validation. This insight is crucial for optimizing lattice design to balance weight, strength, and energy-absorbing capacity effectively. The experimental test result and numerical result showed rather good agreement. It is observed that joint regions, overhang angle, and diameters were the main parameters affecting specimens’ mechanical behavior.

Sound and precise static analysis using a generalization of static single assignment and value numbering

Sound and precise static analysis using a generalization of static single assignment and value numbering

Static and dynamic stabilities of modified gradient elastic Kirchhoff–Love plates

The static and dynamic stabilities of modified gradient elastic Kirchhoff–Love plates (MGEKLPs), which incorporate two length-scale parameters related to strain gradient and rotation gradient effects, are comprehensively analyzed under various load forms and boundary conditions (BCs). The study of static stability employs static balance method and an improved energy method by introducing higher-order deformation gradients and corresponding energy terms. Utilizing the variational method, a sixth-order fundamental buckling differential equation for MGEKLPs under both transverse and in-plane loads is derived, serving as the foundation for the static balance method. The static stability analysis of MGEKLPs examines the combined effects of strain and rotation gradients on size-dependent critical buckling loads. Building on generalized strain energy with higher-order deformation energy, the energy method of classical elastic thin plate model is enhanced and applied to the static stability analysis of MGEKLPs. This approach enables the investigation of static stability without being constrained by the need to solve complex differential equations, making it applicable to various BCs and load scenarios. While static stability provides a description of stable state of an elastic system, dynamic stability offers a more scientific and rigorous analysis. The dynamic stability of simplified gradient elastic Kirchhoff–Love plates (SGEKLPs) with curved edges and different BCs is further investigated by combining the generalized strain energy with Lyapunov’s second stability method, presenting the dynamic stability criterion in the form of norms. A strict description of the dynamic stability of a SGEKLP over the entire time domain is provided for different supporting conditions, including case where all edges are supported and case with free edges. The analysis of size-dependent static and dynamic stabilities offers theoretical guidance for designing elastic thin plates with microstructures.

Enhancing logic-based testing with EvoDomain: A search-based domain-oriented test suite generation approach

ContextEffective software testing requires test adequacy criteria. MC/DC, a widely used logic-based testing criterion, struggles to detect domain errors caused by incorrect arithmetic operations. Domain errors occur when test requirement boundaries shift or tilt, causing unpredictable behavior and system crashes. ObjectiveTo address the inadequacy of MC/DC in detecting domain errors, we present EvoDomain, a search-based testing technique. MethodEvoDomain uses a memetic algorithm combining genetic and hill-climbing algorithms, along with the DBSCAN clustering algorithm to select diversified boundary test data. The memetic algorithm is designed to efficiently enhance the search process for covering boundary test data. We compared EvoDomain with two logic-based testing approaches, a domain-oriented test suite generation approach, and random testing. ResultsEvaluations on 30 case studies show EvoDomain increases fault detection by 74.44% over MC/DC and 65.06% over RoRG. Additionally, EvoDomain improves support for different fault types by up to 68.89% for MC/DC and 66.33% for RoRG. Compared to COSMOS, which uses static analysis, EvoDomain improves the convergence effectiveness of identifying feasible subdomains by 32%. It offers high accuracy (0.99-1) and F1-score (0.99-1). EvoDomain finds the subdomains in less than 1/3 the time of Random search. ConclusionEvoDomain effectively generates domain-oriented test suites, enhancing the accuracy and effectiveness of fault detection.

A cable finite element formulation based on exact tension field for static nonlinear analysis of cable structures

This paper presents a numerically exact cable finite element model for static nonlinear analysis of cable structures. The model derives the exact expression of the tension field using the geometrically exact beam theory coupled with the fundamental mechanical characteristics of cables. The equations for the cable elements are formulated by addressing the equilibrium conditions at the element boundaries and ensuring compatibility within the elements. Unlike previous studies that typically provide explicit expressions for cable models, this study develops a formulation that emphasizes numerical precision and broad applicability. It achieves this by deriving linearized equations with implicit expressions incorporating integrals. The present model accurately computes internal forces and deformation states, and determines the unstrained length of the cable. Additionally, it accounts for the variability in cross-sectional stiffness along the cable's length. The paper discusses solution implementations using the complete tangent matrix and element internal iterations. The effectiveness of the proposed cable elements is demonstrated through numerical examples.

Comparative study of numerical modelling and experimental investigation for vessel-docking operations

A comparative study between numerical modelling and experimental investigation is performed to validate the developed numerical method for simulating floating dock operations with a vessel on board. Both model-scale and full-scale experimental tests are performed on floating docks with a vessel on board, and the draughts using draught meters, floating positions and bending of the floating dock are measured. The present numerical method is proposed based on a quasi-static assumption during vessel-docking operations. A static analysis model is built to determine the static response of a floating dock under a specific ballast water distribution based on a hydrostatic force model and a Newton-Raphson method. A bending model is proposed to calculate the deflection of the floating dock along the longitudinal direction. Results of the mode-scale tests show that the draught measurements and the floating positions of the dock and vessel predicted using the present numerical method agree well with the corresponding experimental results. It proves the accuracy of the present numerical method for simulating vessel-docking operations. Moreover, a well-designed ballast plan enables successful de-ballasting operations on the model-scale dock, even in the event of one to three pump failures. The comparison of the deflection changes of the floating dock in the field test measurements further proves the accuracy of the present bending model. Therefore, the validated numerical model tested on both model-scale and full-scale docks provides a reliable foundation for creating digital twin of floating docks in shipyards.

Structural design and performance testing of respiratory sensor based on optical fiber end-face coupling

An optical fiber sensor based on the principle of intensity modulation is proposed, which is composed of plastic optical fibers and silicone tubes. The displacement measurement is achieved by stretching the optical fibers to cause changes in the angle between the end faces, resulting in changes in the coupling efficiency between the end faces. To address the challenges in the performance calibration of fiber optic respiratory sensors, it is proposed to convert the dynamic characteristics measurement of the respiratory sensor into the static performance analysis of the displacement sensor, so as to obtain the characteristics such as sensitivity, linearity, and repeatability, etc. It is further proposed to use a stepper motor to simulate the periodic stretching process of the optical fibers caused by the respiratory process, enabling the analysis of frequency measurement accuracy under different respiratory strengths. Simulation and experimental results demonstrate that the proposed sensor has high linearity, good repeatability, high sensitivity, and a wide measurement range. It can accurately measure respiratory frequency and display amplitude information, providing comprehensive information for respiratory monitoring.

Hardware information flow tracking based on lightweight path awareness

Vulnerabilities and Trojans in hardware design may cause sensitive data to be leaked and tampered. Information flow tracking technology can effectively verify the confidentiality and integrity of hardware design. Currently, this technology mainly analyzes the reachability of information flow and lacks fine-grained analysis of information flow paths. It is difficult to find structural defects in information flow paths and malicious sensitive information processes in hardware design. To solve above problem, we propose Path-aware Dynamic Information Flow Tracking (PDIFT) technology, which performs taint tracking and path tracking while sensitive information is propagated. It analyzes the propagation of sensitive information in hardware design with fine-grained taint label propagation logic and inserts path label propagation logic only on basic blocks divided by branch nodes, which greatly simplifies the path tracing overhead compared to the full node sequence tracing on the path. Experiments have shown that compared to CellIFT, PDIFT has a 12.1% increase in static analysis time and a 0.1% increase in dynamic validation time. The average instrumentation area cost of each basic block has increased by 16.4 um2. In terms of detection capability, PDIFT makes up for the limitation of false negatives in traditional taint tracking technology through joint analysis of path labels and taint labels, then detect problems such as insufficient iterations of encryption components and malicious processing of important assets, thereby improving the accuracy of hardware security verification.

Comparative analysis of the seismic performance of ECC jacket reinforced columns with different cross-sectional forms subject to different load modes

Based on the high tensile strength and tensile strain of (engineered cementitious composites) ECC, it is applied to the weak link central columns of subway stations to enhance their seismic resilience. In this study, the effects of the column's cross-sectional shape, ECC jacket form, and the vertical gravity load and vertical dynamic load during seismic action on the hysteretic performance of the column were thoroughly analyzed. A constrained constitutive model for cementitious materials, a reinforced hysteresis constitute model, and a calculated damage factor for concrete were adopted to establish a three-dimensional refined column model with an experimentally verified error of less than 10 %. After that, the damage distribution and damage degree of the columns, as well as the changes in hysteretic performance such as hysteretic curve, skeleton curve, energy dissipation, and stiffness degradation were analyzed by the static model analysis. The results showed that the columns had higher damage levels under high frequency and high amplitude of dynamic axial compression ratio in the vertical direction compared to the constant high axial compression ratio, and the ECC jacket could effectively reduce the damage levels of the columns, but the use of the in-built ECC (IB-ECC) jacket was better than the out-sourced ECC (OS-ECC) jacket. In addition, the IB-ECC jacket did not significantly improve the peak bearing capacity of the columns, but significantly improved the ultimate bearing capacity and displacement ductility of the columns, while the OS-ECC jacket significantly improved the peak bearing capacity of the columns. The ECC jacket was also effective in slowing down the stiffness degradation of the columns. This study significantly contributes to the design strategies for enhancing the resilience of columns in subway stations.

Highly sensitive ZnO-doped PET diaphragm-based fiber optic microphone

This study presents a highly sensitive Fiber Optic Microphone (FOM) based on a ZnO-doped PET (PET:ZnO) diaphragm for the first time. The FOM was first simulated and then tested experimentally. Under 14 mPa acoustic pressure and in the frequency range of 1 kHz–20 kHz, the highest SNR of 73.57 dB was measured at 5 kHz. The average signal-to-noise ratio (SNR) in the same frequency range was 51.74 dB. Based on the experimental results, the minimum detectable pressure (MDP) measured at 100 Hz resolution was calculated as low as 2 µPa/Hz1/2. The proposed FOM’s sensitivity was determined to be 150.15 mV/Pa. In addition to the static pressure analysis, a dynamic analysis using the PESQ algorithm was performed to measure the sound quality. With a sound quality score of 3.21, the proposed FOM can compete with commercial microphones. It also has advantages in terms of production and cost. Therefore, the proposed FOM has potential use in various applications, such as voice recognition, real-time communication in extreme environments, and long-distance listening in public/military/private security.

Forced vibrations of an elastic triangular plate supported around its perimeter by a unilateral support via the Chebyshev polynomial expansion

The present study introduces static and dynamic analysis of an elastic triangular plate on unilateral edge supports, including forced vibrations due to loading and unloading excitation. The plate is assumed to be subjected to a uniformly distributed load and an eccentrically applied concentrated load. Furthermore, the loads are assumed to display dynamic variations. The governing equation of the problem is derived by considering the static and the dynamic responses of the plate by including inertia forces. The analytical solution is conducted by employing a series of Chebyshev polynomials for the admissible displacement functions and using Lagrange’s equations of motion. Having found the governing equation of the problem, an approximate numerical solution is accomplished using an iterative process due to the non-linear properties of the unilateral edge supports. The static behavior of the plate under a concentrated load is investigated in detail numerically by considering a wide range of parameters of the plate geometry and the stiffness of the support. In deriving the governing equation of the problem and in the numerical solution, special care is taken to use nondimensional parameters. This approach ensures that the analysis and conclusions remain valid across a wide range of parameter values. Dynamic treatment of the problem is carried out in the time domain by assuming a stepwise time variation of the concentrated load and by employing the constant acceleration procedure in the numerical solution of the system of governing differential equations derived from the equation of motion. Time variations of the displacements, the contact points, and the reactions of the plate’s support are presented in figures for various values of the parameters of the plate, as well as those of the supports, particularly focusing on the non-linearity of the problem due to the plate liftoff from the unilateral support. The effects of the parameters and the loading are investigated in detail. The results reveal that the unilateral property of the support stiffness significantly affects the static and dynamic behavior of the triangular plate. The analysis can be extended easily to cover a general type of loading as well. The main issues addressed in this study include: the analysis of a triangular plate with unilateral perimeter support that does not resist tensile forces; the use of Chebyshev polynomials as admissible functions in both directions; the consideration of static and dynamic loads; the determination of lifting areas of the support in both cases and the assessment of the global vertical force balance in the plate, including inertia forces in the dynamic case.

Research on Predicting the Mechanical Characteristics of Deep-Sea Mining Transportation Pipelines

Deep-sea mining, as a critical direction for the future development of mineral resources, places significant importance on the mechanical characteristics of its transportation pipelines for the safety and efficiency of the entire mining system. This paper establishes a simulation model of the deep-sea mining system based on oceanic environmental loads and the mechanical theory of deep-sea mining transportation pipelines. Through a static analysis, the effective tension along the pipeline length, the maximum values of bending moment, and the minimum values of bending radius are determined as critical points for the dynamic analysis of pipeline mechanical characteristic monitoring. A dynamic simulation analysis of the pipeline’s mechanical characteristics was conducted, and simulation sensor data were obtained as inputs for the prediction model construction. A prediction model of pipeline mechanical characteristics based on the BP neural network was constructed, with the model’s prediction correlation coefficients all exceeding 0.95, enabling an accurate prediction of pipeline state parameters.

Design of a Trailer Adapted for Accommodation and Transport of Beehives

There is relevant interest concerning beehives, taking into account climate change and its influence on bees’ behavior. A part of the industrial engineering sector is focusing on beekeeping applications. More specifically, the present study aims to develop a trailer for the transport of beehives adapted to be placed or fixed to a tractor or a vehicle trailer, with the objective of transporting the beehives safely and stably during transhumance. The proposed novel design relates to a trailer that incorporates a device for housing a rectangular section of the beehives, which can be adapted for fixing or housing in a vehicle or in a vehicle trailer. The device comprises a lower support structure, adapted to support a plurality of rectangular sections of beehives stacked horizontally on the lower structure, an upper frame adapted to house the beehives inside, and two or more connecting elements between the lower structure and the upper frame. The connection of the trailer with the device facilitates the loading and unloading of the beehives by mechanical means. The different parts have been designed as individual pieces and then assembly is carried out to achieve the complete design. This method of implementation is because the simulation of individual components is simpler and easier, since if it is carried out through assembly, the type of joint, such as welding, and the length of the weld would have to be indicated at each point of contact between components, along with its thickness and all the necessary parameters. Therefore, in those welding points, fixed fastenings are indicated and so will simplify it. In accordance with the individual creation of each part, its own load simulation has been carried out. Static analyses are performed taking into account structural elements of this proposed design, with restrictions and loads being established. The analysis, including upper bars and supports, has been completed with several situations. Based on stress values, deformations have been determined and calculations evaluated. The trays have been manufactured using flat steel bars and angled bars for the legs and support of the hives.

Securing Container Images through Automated Vulnerability Detection in Shift-Left CI/CD Pipelines

Integrating shift-left security practices and automated vulnerability detection in container images is imperative for modern software development, given the dynamics and vulnerability landscape. This crucial methodology emphasizes security from the initial stages of integration in container-based environments like Docker and Kubernetes. The paper examines containerization security challenges, including image vulnerabilities, insecure configurations, runtime risks, weak orchestration security, and supply chain weaknesses, while stressing compliance with regulatory rules. It explores how this automated approach leverages vulnerability detection methods integrated into Continuous Integration/Continuous Deployment (CI/CD) pipelines through static and dynamic analyses, vulnerability databases, and policy-enforcement mechanisms. Beyond identifying vulnerabilities in CI/CD pipelines, the paper outlines methods to avoid policy violations, mitigate vulnerable images, and prevent recurring practices. Importantly, it underscores the continuous enforcement and remediation of policies and security standards. Security teams must invest efforts in developing policies, automated executions, and remediation procedures, fostering cross-departmental collaboration. In essence, this proactive stance aims to enhance software security, reduce risks, and improve adherence in containerized ecosystems, making it an indispensable component of modern software development.

牛场补饲推料装置设计与试验

This paper proposed a supplemental feeding pusher based on beef cattle's auxiliary feeding needs to solve the traditional feeding mode of manual work, labor intensity, and inconsistent manual work standards. Firstly, the conveyed feed particles movement process was established as a motion model and the basis of the design parameters of the screw conveyor was explained. ANSYS static analysis module was used to ensure that the structural parameters of the discharging device were reasonable, ANSYS vibration modal analysis module was used to verify the frame strength and stability. According to the theoretical design of the trial prototype, the control system with STM32F103RE microcontroller as the core was carried out. Finally, the orthogonal test was conducted with the screw shaft speed, sweeping roller brush height, and traveling speed as test factors; different parameters were set to verify the effect of supplemental feeding and pushing, and parameter optimization of the test results was carried out using Design-Expert software. The optional combination of working parameters was determined to be the feeding screw shaft speed 188 r/min, the sweeping roller brush speed 160 r/min, and the work speed 0.26 m/s. The test demonstrated that the residual feed width was 0.73 m, and the transverse coefficient of variation was 14.9%, which could satisfy the needs of auxiliary feeding for beef cattle. This study reduced feed waste and met the cattle feeding needs to the greatest extent, and it could provide a reference for auxiliary feeding machinery.

WCET Analysis Based on Micro-Architecture Modeling for Embedded System Security

To ensure the timely execution of hard real-time applications, scheduling analysis techniques must consider safe upper bounds on the possible execution durations of tasks or runnables, which are referred to as Worst-Case Execution Times (WCET). Bounding WCET requires not only program path analysis but also modeling the impact of micro-architectural features present in modern processors. In this paper, we model the ARMv8 ISA and micro-architecture including instruction cache, branch predictor, instruction prefetching strategies, out-of-order pipeline. We also consider the complex interactions between these features (e.g., cache misses caused by branch predictions and branch misses caused by instruction pipelines) and estimate the WCET of the program using the Implicit Path Enumeration Technique (IPET) static WCET analysis method. We compare the estimated WCET of benchmarks with the observed WCET on two ARMv8 boards. The ratio of estimated to observed WCET values for all benchmarks is greater than 1, demonstrating the security of the analysis.