Maximum Lifting Capacity Research Articles

Design and Scalable Fast Fabrication of Biaxial Fabric Pouch Motors for Soft Robotic Artificial Muscle Applications

Soft pouch motors, engineered to mimic the natural movements of skeletal muscles, play a crucial role in advancing robotics and exoskeleton development. However, the fabrication techniques often involve multistage processes; they lack soft sensing capabilities and are sensitive to cutting and damage. This work introduces a new textile‐based pouch motors with the capacity for biaxial actuation and capacitive sensory functions, achieved through the application of computerized knitting technology using ultrahigh molecular weight polyethylene yarn (Spectra) and conductive silver yarns. This method enables the rapid and scalable mass fabrication of robust pouch motors. The resulting pouch motors exhibit maximum lifting capacity of 10 kg, maximum contraction of 53.3% along the y‐axis, and transverse extension of 41.18% along the x‐axis at 50 kPa pressure. Finite element analysis closely matches the experimental data. The capacitance signals in relation to contraction motion are well suited for detecting air pressure levels and hold promise for applications requiring robotic control. Notably, it effectively elevates an ankle joint simulator at a 20° angle, highlighting its potential for applications such assisting individuals with foot drop. This study presents a practical demonstration of the soft ankle exosuit designed to provide lifting support for individuals facing this mobility challenge.

The highs and lows of lifting loads: SPM analysis of multi-segmental spine angles in healthy adults during manual handling with increased load

Introduction: Manual handling personnel and those performing manual handling tasks in non-traditional manual handling industries continue to suffer debilitating and costly workplace injuries. Smart assistive devices are one solution to reducing musculoskeletal back injuries. Devices that provide targeted assistance need to be able to predict when and where to provide augmentation via predictive algorithms trained on functional datasets. The aim of this study was to describe how an increase in load impacts spine kinematics during a ground-to-platform manual handling task. Methods: Twenty-nine participants performed ground-to-platform lifts for six standardised loading conditions (50%, 60%, 70%, 80%, 90%, and 100% of maximum lift capacity). Six thoracic and lumbar spine segments were measured using inertial measurement units that were processed using an attitude-heading-reference filter and normalised to the duration of the lift. The lift was divided into four phases weight-acceptance, standing, lift-to-height and place-on-platform. Statistical significance of sagittal angles from the six spine segments were identified through statistical parametric mapping one-way analysis of variance with repeated measures and post hoc paired t-tests.Results: Two regions of interest were identified during a period of peak flexion and a period of peak extension. There was a significant increase in spine range of motion and peak extension angle for all spine segments when the load conditions were increased (p < 0.001). There was a decrease in spine angles (more flexion) during the weight acceptance to standing phase at the upper thoracic to upper lumbar spine segments for some condition comparisons. A significant increase in spine angles (more extension) during the place-on-platform phase was seen in all spine segments when comparing heavy loads (>80% maximum lift capacity, inclusive) to light loads (<80% maximum lift capacity) (p < 0.001).Discussion: The 50%–70% maximum lift capacity conditions being significantly different from heavier load conditions is representative that the kinematics of a lift do change consistently when a participant’s load is increased. The understanding of how changes in loading are reflected in spine angles could inform the design of targeted assistance devices that can predict where and when in a task assistance may be needed, possibly reducing instances of back injuries in manual handling personnel.

Performance Analysis of Motorized Object Lifting Toggle Jack

This study seeks to develop a motorized car jack with maximum lifting capacity of 1.5 tons. The principle of the existing car jack was modified by making adjustments and using a prime mover which is the electric motor to control the lifting operation of the jack. The design incorporates an electric motor that is powered by a 12-volt battery of a small vehicle and the device is connected through a cigarette lighter adapter in the vehicle. The common challenge with the currently available car jacks on the market is that they are manually operated and need a substantial amount of physical effort is required to lift the vehicle. In this work, human effort was eliminated in raising the jack by the use of the torque generated by the motor as it rotates. The use of long cablings to control the motorized operation assists the jack to be safe to use as the operator can use the jack in a comfortable position and as far away from the vehicle as possible. The performances of the machine at different loads were calculated. The approximate values and graphical relationships were established. Using MS Excel. It was established that, the machine had efficiency of about 53%. The investigation revealed that the minimal efficiency was as a result of the great frictional forces between the screw and the threaded base required to be overcome as well as the capacity of the DC motor and gear system.

LNG Type C, Cylindrical Weight Design Limitation Based on Shipbuiding Facilities

Supporting climate change mitigation and sustainable energy due to its ability to reduce CO2, Liquefied Natural Gas (LNG) considered as promising alternative fuel. In a particular small market with LNG demand between 2,500 m3 to 7,500 m3, utilization of LNG type-C, cylindrical tanks are compatible to use in small-scale LNG carrier. In order to overcome these challenges, Indonesian industry need to design the tank’s volume and weight requirements.while also taking into account the capabilities of the shipbuilding facilities. The weight of the tank, which comprises the weight of the outer tank and dished end, are the decision variable in the approach for weight estimation analysis, which carried by using using extrapolation to search optimum diameter and length of the tank The objective function is maximization of the tank capacity. The capability of the lifting equipment in the shipyard is the limitation used in this paper. This research data is based on the shipyard capability of PT. PAL Indonesia, PT. Dok dan Perkapalan Kodja Bahari (Persero), PT. Industri Kapal Indonesia, and PT. Batamec Shipyard. Result obtained that maximum volume of 5,663.369 m3 LNG type C, weight about 450.671 tons with maximum crane lifting capacity in shipyard are 500 tons

DESAIN ALAT CABUT SINGKONG SISTEM SLING OTOMATIS UNTUK DIGUNAKAN PADA PROSES PANEN

The design of the cassava extractor in this study differs from the existing concept where the automatic cassava extractor uses only a small amount of human power. The purpose of this study was to design a cassava extractor using an automatic sling system to facilitate farmers in the cassava harvesting process, thereby reducing the level of injury or pain in the farmers' backs and shoulders in the long term. This research is an applied research that uses the facto exposure method to solve practical problems in everyday life. The result of this research is the design of the cassava extractor using an automatic system which is an improvement from the concept that has been made, has differences and advantages compared to the previous concept because it uses little human power, namely when wrapping the rope at the base of the cassava stem and pressing the control button. hoist crane, this tool is more flexible, easy to carry anywhere, more practical because its use just presses the up/down button on the automatic sling. In addition, this cassava extractor is more effective where with a maximum lifting capacity of 500 kg and through an intermediary sling that has been tested by SNI. This tool is able to lift more than one cassava stick at the same time for 20 seconds. Keywords: Automatic, cassava extractor, design

Perancangann Alat Angkat Mesin Mobil Sistem Hidrolik

This lifting device is for lifting and lowering loads supported by truss mechanism and a hydraulic jack with a maximum lifting capacity of 480kg. The device focuses on lifting the car engines with a lifting mechanism consisting of strusses, a hydraulic jack capacity of 3 tons, and a chain package with hooks to hang the load. Method of this research is a library research as main sources to design the device. Outcome of this research is a design of lifting device for maximum lifting capacity of 400 k. Material of hook is steel carbon S45C with a maximum tensile stress of 13.26 kg/mm2 . Lifting chain is made of steel alloys Grade 80 with a maximum tensile stress of 187.37 N/mm2 . Truss is selected made of carbon steel S30C with a maximum compress stress of 442.47 kg/cm2 and all of the working stresses are below the allowable stress limits, thus the device is safe to be used.Key words: lifting, Design, Hydraulic

ANALYSIS ON ANTI-OVERTURNING STABILITY OF A TRUCK CRANE BASED ON ZERO MOMENT POINT THEORY

Truck crane stability has been a hot research issue. It is a conventional method used to calculate the moments equilibrium when analyzing stability. However, errors can occur because of the lack of dynamic simulation in conventional methods. Hence, to minimize errors, this study utilized the zero moment point (ZMP) theory to calculate the maximum lifting capacity of the truck crane considering the dynamic load, and proposed an anti-overturning detection method based on the theory. First, the model of the truck crane was established and the solution formula of ZMP was obtained. From the Lagrange equation, the dynamic model of payload oscillations was analyzed during crane operations. Second, the ZMP theory was used to analyze the stability of the truck crane and derive the maximum payload. Next, the experiment was conducted to measure the pressure of the four outriggers and their center of pressure (CoP) during hoisting, luffing, and slewing operations were calculated. Compared to stable movement, the CoP would vibrate irregularly, consequently reducing the lifting capacity of unstable motion. Finally, the anti-overturning detection method is proposed based on ZMP and CoP. Results demonstrate that the reduction of lifting capacity is caused by the dynamic load. The payload swing has a larger effect on the maximum lifting capacity than hoisting, luffing, and slewing motions. The maximum payload can decrease with the increase of the swing angle. The proposed method provides a correct judgment on the stability of the truck crane, which can accurately predict the overturning state of the crane and reduce the risk in the operation. Keywords: truck crane, overturning, zero moment point, center of pressure, stability

Influence of load knowledge on lifting biomechanics

Objectives. Findings from previous studies implied that appropriately controlling load knowledge might help improve the biomechanical performance during lifting tasks. However, only load weight knowledge was often discussed in previous studies. The current study aimed to complement the existing studies and provide improved knowledge about the influence of load knowledge on lifting biomechanics. Methods. Twenty-four healthy male participants were recruited and instructed to perform symmetric lifting tasks with different load weights under different load knowledge conditions. Load weights were set at three levels (40, 80 and 120%) of each participant’s maximum acceptable lifting capacity. The examined load knowledge conditions included ‘no knowledge’ condition, ‘weight known’ condition, ‘fragile material known’ condition and ‘weight and fragile material known’ condition. Results. We found that when knowing fragility information about lifting materials, workers tended to be more cautious by adopting a less dynamic motion pattern during the landing phase, as evidenced by decreases of 6–8% in elbow joint acceleration. The ‘cautious’ lifting pattern when fragility load knowledge was presented could contribute to reduced risk of lower back disorder. Conclusion. This finding could help to develop lower back disorder prevention interventions to improve occupational safety and health.

Finite Element Fatigue Analysis of Unsupported Crane

Abstract The presented strength and fatigue calculations refer to an unsupported deck crane and its three distinct parts: housing, jib and column. Static loads applied to the structure were due to the crane’s own weight and a maximum working load, corresponding to a maximum lifting capacity at a maximum outreach of the crane. The numerical analysis was aimed at determining the thickness of the skin plating of the column and the number, shape and distribution of stiffeners in the column, housing and jib, ensuring that the crane yields correct strength and fatigue parameters. During the process of designing marine structures, the standard numerical analysis is, in many cases, limited to calculations in the basic strength range. Even when using numerical methods of analysis, complex strength and fatigue calculations are often not performed. The modern numerical analysis chain for marine structures should concentrate not only on strength analysis, but should take a further step, which encompasses fatigue analysis. The article presents a new outlook on design methods, which should be the entry point to the design of marine structures. Based on the acquired number of cycles of fatigue life, it is possible to estimate, with a sufficient degree of accuracy, the practical service life of a structure. To solve the problem, the authors used the finite element analysis software ABAQUS supported by the fe-safe system.

Feature Detection and Biomechanical Analysis to Objectively Identify High Exposure Movement Strategies When Performing the EPIC Lift Capacity test.

Purpose The Epic Lift Capacity (ELC) test is used to determine a worker's maximum lifting capacity. In the ELC test, maximum lifting capacity is often determined as the maximum weight lifted without exhibiting a visually appraised "high-risk workstyle." However, the criteria for evaluating lifting mechanics have limited justification. This study applies feature detection and biomechanical analysis to motion capture data obtained while participants performed the ELC test to objectively identify aspects of movement that may help define "high-risk workstyle". Method In this cross-sectional study, 24 participants completed the ELC test. We applied Principal Component Analysis, as a feature detection approach, and biomechanical analysis to motion capture data to objectively identify movement features related to biomechanical exposure on the low back and shoulders. Principal component scores were compared between high and low exposure trials (relative to median exposure) to determine if features of movement differed. Features were interpreted using single component reconstructions of principal components. Results Statistical testing showed that low exposure lifts and lowers maintained the body closer to the load, exhibited squat-like movement (greater knee flexion, wider base of support), and remained closer to neutral posture at the low back (less forward flexion and axial twist) and shoulder (less flexion and abduction). Conclusions Use of feature detection and biomechanical analyses revealed movement features related to biomechanical exposure at the low back and shoulders. The objectively identified criteria could augment the existing scoring criteria for ELC test technique assessment. In the future, such features can inform the design of classifiers to objectively identify "high-risk workstyle" in real-time.

Resistance-exercise training ameliorates LPS-induced cognitive impairment concurrent with molecular signaling changes in the rat dentate gyrus.

Effective treatments preventing brain neuroinflammatory diseases are lacking. Resistance-exercise training (RT) ameliorates mild cognitive impairment (MCI), a forerunner to neuroinflammatory diseases. However, few studies have addressed the molecular basis by which RT abates MCI. Thus experiments were performed to identify some molecular changes occurring in response to RT in young, female Wistar rats. To induce MCI, intraventricular lipopolysaccharide (LPS) injections were used to increase dentate gyrus inflammation, reflected by significantly increased TNF-α (~400%) and IL-1β (~1,500%) mRNA (P < 0.0001) after 6 wk. Five days after LPS injections, half of LPS-injected rats performed RT by ladder climbing for 6 wk, 3 days/wk, whereas half remained without ladders. RT for 6 wk increased lean body mass percentage (P < 0.05), individual muscle masses (gastrocnemius and tibialis anterior) (P < 0.05), and maximum lifting capacity (P < 0.001). The RT group, compared with sedentary controls, had 1) ameliorated spatial learning deficits (P < 0.05), 2) increased dentate gyrus phosphorylation of IGF-1R, protein kinase B, and GSK-3β proteins (P < 0.05), components of downstream IGF-1 signaling, and 3) increased dentate gyrus synaptic plasticity marker synapsin protein (P < 0.05). Two follow-up experiments (without LPS) characterized dentate gyrus signaling during short-term RT. Twenty-four hours following the third workout in a 1-wk training duration, phosphorylation of ERK1/2 and GSK-3β proteins, as well as proliferation marker protein, PCNA, were significantly increased (P < 0.05). Similar changes did not occur in a separate group of rats following a single RT workout. Taken together, these data indicate that RT ameliorates LPS-induced MCI after RT, possibly mediated by increased IGF-1 signaling pathway components within the dentate gyrus. NEW & NOTEWORTHY The data suggest that resistance-exercise training restores cognitive deficits induced by lipopolysaccharides and can activate associated IGF-1 signaling in the dentate gyrus. Our data show, for the first time, that as few as three resistance-exercise workouts (spread over 1 wk) can activate IGF-1 downstream signaling and increase proliferation marker PCNA in the dentate gyrus.

Lifting Capability and Stress Analyses of the Crane System for a Large-Sized Tactical Wrecker

A large-sized tactical wrecker is a special-purpose vehicle that lifts and tows tactical vehicles and heavy loads. It consists of a crane, a post structure, outriggers and a suitable chassis truck, and during its initial design, the structural safety and tipping stability should be preemptively examined in terms of the layout of these components. This paper proposes computer-aided engineering (CAE) methods to evaluate the maximum lifting capacity of the wrecker and the structural safety of its crane during the initial design. The analytical model for the large-sized wrecker is constructed with 236 degrees of freedom by combining the crane system developed using the ADAMS macros with the dynamic model of large chassis truck with an axle suspension. The design parameters for the wrecker model that influence the tipping stability are selected, and then the maximum lifting loads with the corresponding changes are calculated. This parametric study shows that the characteristics of the boom and the layout of the outriggers greatly affect the maximum lifting capacity. Finite element (FE) analyses of the 1st stage boom and the 3rd stage boom show the stresses under the maximum overturning moment condition are within the allowable strength.

Influence of age on lifting capacity among manual materials handlers.

Recommended weight limit for manual materials handlers has to be decided based on the individual characteristics of the person and age is one of the major variable affecting maximal lifting capacity. But there is limited information on pattern of change in lifting capacity with age. To determine the influence of age on the maximum acceptable weight of lift among manual materials handlers. Two hundred and seventeen male construction workers were grouped into four age quotas- 19-28, 29-38, 39-48 and 49-58 years. Lifting capacity was determined using progressive isoinertial lifting evaluation, adopting semi-squat technique of lifting at two levels: waist and shoulder. A statistically significant increase in the maximum acceptable weight was observed from first to second age group followed by a gradual decline. The percentage of decline from second to third age group was 11.89% and 14.34% and from third to fourth age group was 5.60% and 19.90% for waist and shoulder level respectively. Pattern of change in lifting capacity with age among manual materials handlers has been investigated in this study. Lifting capacity was found to be the greatest in 29-38 year age group, therefore prescribing recommended weight limit uniformly for all the workers may not be the best practice.

Optimization of crane setup location and servicing schedule for urgent material requests with non-homogeneous and non-fixed material supply

Abstract Reducing hook movement distances could decrease crane operation times to deliver heavyweight materials in construction sites. Conventional scheduling methods include first-in-first-serve (FIFS), shortest-job-first (SJF), nearest-neighbor-first (NNF), and Traveling salesman problem (TSP). A new optimization model to optimize crane setup location, hook movement sequences and servicing schedules serving all supply and demand locations is proposed. Proposed model is able to model homogeneous and non-homogeneous material supply. Initial hook location can be given as input for optimization. Fixed material supply and demand location pairs are relaxed as model variables. Maximum crane lifting capacity is considered and multiple hook movement trips between material supply and demand locations are modeled if requested material weights exceed this maximum crane lifting capacity. Users may place “urgent” material demand requests and the proposed optimization model can optimize a servicing sequence to prioritize all urgent requests. The problem is formulated as a Binary-Mixed-Integer-Linear-Program (BMILP) which is solved by standard branch-and-bound techniques. Significant reduction in total operation time is achieved while comparing to other conventional scheduling strategies.

Real-time simulation model for dynamic analysis of three-wheel counterbalance forklift

Modern multibody simulation techniques enable the explicit description of complex mechanical systems such as mobile and industrial machinery into relevant equations of motion. The subsequent solution of the equations of motion can lead to simulation in real-time. Presently, real-time simulation models based on multibody dynamics can account for a large number of rigid and flexible bodies as well as contact descriptions. It enables the inclusion of physical phenomena and user feelings associated with multibody systems in the real-time simulation. These specifications can be used in a number of product processes including user training and product development. The present study applies real-time multibody simulation to a three-wheel, two-ton counterbalance forklift. The forklift simulation model includes rigid bodies, joints, a contact model, friction forces, power transmission, and a steering mechanism. The study reports aspects associated with forklift performance such as speed, speed reduction around a curved path, mast wobbling, maximum lifting capacity, and vibrations during the lift. The simulation model is verified by comparing the speed, acceleration, mast lift and tilt speeds with the measurements of a reference forklift.

Real-time simulation model for dynamic analysis of three-wheel counterbalance forklift

Modern multibody simulation techniques enable the explicit description of complex mechanical systems such as mobile and industrial machinery into relevant equations of motion. The subsequent solution of the equations of motion can lead to simulation in real-time. Presently, real-time simulation models based on multibody dynamics can account for a large number of rigid and flexible bodies as well as contact descriptions. It enables the inclusion of physical phenomena and user feelings associated with multibody systems in the real-time simulation. These specifications can be used in a number of product processes including user training and product development. The present study applies real-time multibody simulation to a three-wheel, two-ton counterbalance forklift. The forklift simulation model includes rigid bodies, joints, a contact model, friction forces, power transmission, and a steering mechanism. The study reports aspects associated with forklift performance such as speed, speed reduction around a curved path, mast wobbling, maximum lifting capacity, and vibrations during the lift. The simulation model is verified by comparing the speed, acceleration, mast lift and tilt speeds with the measurements of a reference forklift.

Systematic Review and Meta-Analysis of Predictors of Military Task Performance: Maximal Lift Capacity.

Hydren, JR, Borges, AS, and Sharp, MA. Systematic review and meta-analysis of predictors of military task performance: maximal lift capacity. J Strength Cond Res 31(4): 1142-1164, 2017-Physical performance tests (e.g., physical employment tests, return-to-duty tests) are commonly used to predict occupational task performance to assess the ability of individuals to do a job. The purpose of this systematic review was to identify predictive tests that correlate well with maximal lifting capacity in military personnel. Three databases were searched and experts in the field were contacted, resulting in the identification of 9 reports confined to military personnel that presented correlations between predictor tests and job tasks that measured maximal lift capacity. These 9 studies used 9 variations of a maximal lift capacity test, which were pooled to evaluate comparisons. The predictive tests were categorized into 10 fitness domains, which in ranked order were as follows: body mass and composition, absolute aerobic capacity, dynamic strength, power, isometric strength, strength-endurance, speed, isokinetic strength, flexibility, and age. Limitations of these data include a restricted age range (95% confidence interval [95% CI], 20-35; no correlations to maximal lift capacity) and the limited number of comparisons available within the cited studies. Weighted mean correlations ((Equation is included in full-text article.)) and 95% CI were calculated for each test. Lean body mass (kg) was the strongest overall predictor ((Equation is included in full-text article.); 95% CI, 0.697-0.966). Tests of dynamic strength had stronger correlations than strength endurance ((Equation is included in full-text article.), 95% CI, 0.69-0.89 vs. (Equation is included in full-text article.), 95% CI, 0.21-0.61). The following 6 domains of physical performance predictive tests had pooled correlations of 0.40 or greater for combined-sex samples: dynamic strength, power, isometric strength, strength endurance, speed, and isokinetic strength. Anthropometric measures explain 24-54% of maximal lift capacity variance, and lean body mass alone accounts for ∼69%. This review provides summarized information to assist in the selection of predictive tests for maximal lifting capacity in military personnel.

Asymmetry costs: effects of wing damage on hovering flight performance in the hawkmoth Manduca sexta.

Flight performance is fundamental to the fitness of flying organisms. Whilst airborne, flying organisms face unavoidable wing wear and wing area loss. Many studies have tried to quantify the consequences of wing area loss to flight performance with varied results, suggesting that not all types of damage are equal and different species may have different means to compensate for some forms of wing damage with little to no cost. Here, we investigated the cost of control during hovering flight with damaged wings, specifically wings with asymmetric and symmetric reductions in area, by measuring maximum load lifting capacity and the metabolic power of hovering flight in hawkmoths (Manduca sexta). We found that while asymmetric and symmetric reductions are both costly in terms of maximum load lifting and hovering efficiency, asymmetric reductions are approximately twice as costly in terms of wing area lost. The moths also did not modulate flapping frequency and amplitude as predicted by a hovering flight model, suggesting that the ability to do so, possibly tied to asynchronous versus synchronous flight muscles, underlies the varied responses found in different wing clipping experiments.

OPINIONS ABOUT ALLOTTING STRAINS ON THE LAYERS OF A LAMINATED MONOLITH COMPOSITE

A previous paper stated the method of determination of the neutral surface of a composite monolithic, laminate composite, organizing some of the component layers, go to the method of distribution of tasks developed in one given case. This regard illustrates several possible options of which results can enable a proper assessment of the maximum strains and alignment layers, ensuring a maximum lifting capacity. The study can be developed to optimize the organization of layers, depending on the practical purpose of using the composite structure (mechanical, thermal and / or sound).

Lifting speed preferences and their effects on the maximal lifting capacity.

The objectives of this study were to evaluate how lifting capacity and subjective preferences are affected by different lifting speeds. The maximum lifting capacity of lift was determined with three independent variables, lifting speed, lifting technique, and lifting height. Questionnaires were evaluated after the experiment by the participants for the lifting speed preferences. This study found that the lifting speed was a significant factor in the lifting capacity (p<0.001); and the lifting height (p<0.001) and the interaction of lifting speed and lifting height (p=0.005) affected the lifting capacity significantly. The maximal lifting capacity was achieved around the optimal speed that was neither too fast nor too slow. Moreover, the participants’ preferred lifting speeds were consistently close to the optimal lifting speed. The results showed that the common lifting practice guideline to lift slowly might make the worker unable to generate a large lifting capacity.