Eng

Soil compaction significantly affects crop growth and yield. Traditional methods for assessing soil density are labor-intensive, time-consuming, and provide limited coverage of the entire field. This study aims to evaluate an alternative method for measuring soil density in real time during standard cultivation operations. The proposed approach involves measuring the elastic deformation of the cultivator shank using strain gauges mounted on the working element. Simultaneous measurement of two separate working elements was tested. Data were recorded in real time and used to generate a soil compaction map of the test field. Soil density measurements obtained using a vertical cone penetrometer served as a reference for comparison. Analysis of the collected data revealed a strong correlation between shank deformation and measured soil density, with a Multiple R = 0.814 and R² = 0.662. The results demonstrate that elastic deformation of the cultivator shank can reliably indicate soil compaction. The tested methodology provides a practical, real-time assessment of soil density during cultivation. It can be integrated into various plows or cultivators, enabling continuous monitoring of soil compaction without the labor and fuel demands of traditional mechanical tests. This approach offers a promising tool for precision soil management and optimizing field operations.

Composite steel–concrete beams have gained significant attention in modern construction due to their superior structural efficiency, economic viability, and adaptability to diverse applications. This paper presents a comprehensive review of research developments related to both conventional and post-tensioned composite beam systems. Emphasis is placed on the structural behavior, design considerations, and performance improvements achieved through external post-tensioning using high-strength tendons. Such systems enhance ultimate load capacity, extend the elastic range before yielding, and reduce the required amount of structural steel, thereby improving material efficiency and reducing construction costs. The review also examines the influence of tendon application timing, connection type, and load conditions in both positive and negative bending regions. By synthesizing experimental and analytical findings, this study identifies key advantages, limitations, and research needs in optimizing the design and performance of steel–concrete composite beams. The insights presented herein aim to guide engineers, researchers, and practitioners in advancing the application of composite beam strengthening techniques in modern infrastructure.

This study develops empirical equations relating viscous damping ratios (ξ) and damper coefficients (c) in steel structures for seismic design applications. The objective is to establish predictive formulas that enable conversion between equivalent viscous damping ratios and physical damper characteristics through dynamic analysis. This research employs a two-phase analytical methodology on steel building frameworks. Initially, inherent viscous damping ratios are incrementally varied from 3% to 40% to establish baseline response characteristics. Subsequently, supplemental damping devices are integrated with damper coefficients (c) adjusted according to manufacturer specifications. Linear time-history analyses are conducted for both configurations to determine equivalent damping relationships, with a particular focus on Interstory Drift Ratios (IDR) and Peak Floor Accelerations (PFA) as key seismic demand parameters. By comparing response quantities between inherent and supplemental damping scenarios, empirical relationships linking physical damper coefficients with equivalent viscous damping ratios are formulated. The resulting equations provide practicing engineers with a practical tool for estimating damper specifications based on target damping levels in steel structures. The formulations are derived from linear time-history analysis of steel frame configurations and are applicable within the scope of linear elastic response and viscous damper behavior consistent with typical design conditions.