Full Plastic Research Articles

Reduced plastic film mulching under zero tillage boosts water use efficiency and soil health in semiarid rainfed maize field

Reducing the amount of plastic film while maintaining high water use efficiency & soil health is a huge challenge globally. A two-year field investigation showed that full and half plastic film mulching harvested greater in-season rainfall infiltration into soils, and significantly greater grain yield and water use efficiency under the no-tillage conditions than under the tillage conditions. Among the no-tillage treatments, half plastic film mulching resulted in significantly greater soil light fraction organic carbon by 42.7% and particulate organic carbon by 41.2% than full plastic film mulching respectively, due to its enhanced extramatrical hyphal length, glomalin production and root biomass input. Owing to higher water availability, soil nutrient uptake was accordingly enhanced under no-tillage. This phenomenon was tightly correlated with the improved abundance of arbuscular mycorrhizal fungi. Therefore, it might be feasible and efficient to massively reduce plastic mulching but improve water use efficiency and soil health in semiarid environment.

Carbon reduction and strength enhancement in functionally graded reinforced concrete beams

The production of cement alone is responsible for 5–8% of global CO2 emissions. This high environmental footprint can be partly attributed to inefficiencies at the material and structural level in concrete structures. Although the performance requirements vary spatially within a structural element, a single concrete with the same properties is typically used ubiquitously, instead of being tailored to the requirements. This leads to inefficiencies in concrete utilisation and embodied carbon. This research addresses these inefficiencies and investigates a novel approach to the enhancement of the environmental and mechanical performance of reinforced concrete structures. Shear-critical elements with a shear span-to-depth ratio of 2.5, a longitudinal reinforcement ratio below 1.3% and no transverse reinforcement were tested to failure. Functionally graded concrete and voids were used to engage a preferential internal resisting mechanism reliant on the internal arch action. Volumes that were superfluous or detrimental were either cast with a lightweight concrete and with lower embodied carbon, or left unfilled. Novel geometries were developed through an innovative fabrication methodology with removable inserts, achieving wet-on-wet interfaces between concrete mixes. Net increases in performance were achieved in all specimens compared to conventional prismatic reference beams. In the specimen with the highest performance, the overall resistance almost doubled whilst the calculated embodied carbon was reduced by approximately a third. The strategic use of functional grading and voids altered the cracking pattern and the development of critical shear cracks in particular. The initiation, evolution and propagation of cracks was engineered to preserve the preferential resisting mechanism. Specimens were consequently allowed to deform and divert damage away from the internal arch. As a result, brittle shear failures were delayed or prevented. In the most beneficial cases, the full plastic flexural capacity of the specimens was developed through yielding of the steel reinforcement. These findings lead to a better fundamental understanding of damage, cracking and shear behaviour in reinforced concrete. They demonstrate the potential for a new generation of more sustainable reinforced concrete structures with higher mechanical resistance and lower environmental impact.

Ameliorating C and N balance without loss of productivity by applying mulching measures in rainfed areas

Farmland mulching is applied widely as a soil management practice, especially in rainfed areas with scarce water resources. However, it is not clear how continuous mulch application might affect the carbon and nitrogen budget in rainfed agroecosystems. Therefore, we evaluated the impacts of different mulching measures (SM: flat planting pattern with full straw mulching; RM: ridge–furrow construction with half plastic film mulching; PM: flat planting pattern with full plastic film mulching; BM: flat planting pattern with full biodegradable film mulching; and NM: conventional tillage without mulching) on the maize yield, net ecosystem carbon budget (NECB), net global warming potential (NGWP), greenhouse gas intensity (GHGI), and N surplus or deficiency. The results showed that compared with NM, the maize yield decreased significantly by 10.0% under SM, whereas the mulching treatments (RM, PM, and BM) significantly increased the maize yield by 15.1–24.4% (P < 0.05). SM, RM, and PM significantly increased CO2 emissions (24.8–38.2%), N2O emissions (21.1–47.1%), and NGWP (20.8–45.5%), but reduced NECB. By contrast, BM increased NECB and significantly reduced GHGI (P < 0.05). Regardless of the mulching method applied, the N balance indicated an N surplus. Each mulching treatment (SM, RM, PM, and BM) increased the harvested N removal (47.9–179.9 kg N ha–1) and decreased the N leaching loss (8.8–35.9 kg N ha–1). RM, PM, and BM inhibited the ammonia volatilization rate, whereas SM promoted it. PM and BM achieved a lower N surplus. In conclusion, biodegradable film mulching (BM) can significantly reduce GHGI and the risk of N losses while also ensuring high crop yields, and thus it can be used as a high-yield and sustainable production method in rainfed areas.

Elastic and plastic deformation of surface asperities and their load-carrying mechanisms during the formation of a real contact area

How the contact behaviours of steel engineering surfaces with different roughnesses (Ra = 0.1, 0.6 and 1.0 µm) are affected by the asperity work-hardening and the deformation regime are described here. Large values of the plasticity index Ψ between 20 and 50 indicate that all the surfaces should undergo a full plastic deformation. However, in the loading range up to the yield stress (on a nominal contact area) the rough surfaces exhibited at least 10 % elastic deformation, while for the smooth surfaces the elastic deformation was as much as 44 %. During the loading, the work-hardening increased the hardness of the rough surfaces by up to 63 %, and that of the smooth surfaces by up to 20 %. However, the asperities were able to carry the load that resulted in as much as a 4–10-times-higher contact pressure than the (initial) bulk yield strength. The proposed contact mechanisms for such an increased asperity-load-carrying capacity depend on the surface roughness. For the rough surfaces this is due to the work-hardening, while for the smooth surfaces the dominant mechanisms enhancing the load-carrying capacity are the work-hardening combined with the hydrostatic bulk stresses.

Out-of-plane crushing performances of cell-based hierarchical honeycombs based on the evaluation criteria for ideal energy absorption

A cell-based hierarchical strategy was introduced in the preparation of traditional honeycombs to design a novel structure, known as cell-based quadrangular hierarchical honeycombs (CQHHs). The out-of-plane crashworthiness of CQHHs was investigated using experimental, numerical, and analytical methods. The criteria of ideal energy absorption were employed to evaluate the crushing performance. Then, the effects of a hierarchical strategy and geometric parameters, including the cell densities of macrocells and microcells, the relative density, and the thickness coefficient, on the crushing performance of the CQHHs were tested. Consequently, the optimal hierarchical strategy, namely, the completely ordered arrangement (COA) was identified, and a parameter analysis demonstrated that the cell density and thickness coefficient effectively improved the energy absorption efficiency of the CQHHs. Based on the combination of the COA strategy and optimal parameters, an improvement of 74.45% in energy absorption efficiency was observed, compared with a traditional honeycomb with 3 × 3 cells. The mean crushing force (MCF) reached 96.24% of the full plastic strength of the matrix, indicating that the ideal energy absorption could be closely approached by the cell-based hierarchical honeycomb. These achievements provide an effective way for developing lightweight energy absorbers and achieving ideal energy absorption.

Flat metamorphic InAlAs buffer layer on GaAs(111)A misoriented substrates by growth kinetics control

We have successfully grown, through the detailed control of the growth kinetics, flat InAlAs metamorphic buffer layers on 2∘-off GaAs(111)A substrates using molecular beam epitaxy. Almost full plastic relaxation is obtained for a layer thickness > 40 nm. The control of an adatom diffusion length and a step ejection probability from the bunches permits a reduction of the InAlAs epilayer root-mean-square surface roughness to 0.55 nm.

A Fractal Contact Model for Rough Surfaces considering the Variation of Critical Asperity Levels

A contact model for rough surfaces based on the fractal theory is proposed in the present work. Firstly, the deformation of the material is divided into four stages: elastic deformation, the first elastoplastic deformation, the second elastoplastic deformation, and full plastic deformation. And the variation of material hardness is considered when analyzing the contact characteristics of a single asperity within the first and second elastoplastic deformation stages. Secondly, the size distribution function of contact spots at different frequency levels is derived. And the expressions of asperity critical frequency levels are rederived. Lastly, the feasibility and credibility of the proposed model are verified by comparison with other contact models and experimental data. The results show that when the variation of the material hardness is considered, the contact area of a single asperity in the first elastoplastic deformation stage becomes larger, while the contact area of a single asperity in the second elastoplastic deformation stage becomes smaller. Moreover, the critical asperity frequency levels of the rough surface are not constant, but the variables are related to the total real contact area of the rough surface and decrease as the real contact area increases. The proposed model is a modification and improvement of the existing fractal contact models, which can lead to a more accurate relationship between the contact load and the total real contact area of the rough surface.

Mechanical properties of shear-type hysteretic dampers supported by studs

The shear-type hysteretic damper of an energy-absorbing member reduces the damage to the main member, such as column or beam, by absorbing seismic energy as the shear deformation of steel. As a support element for connecting the damper to the structure, brace-type and stud-type systems are mainly used. In the stud support, the stress transmission mechanism to the damper is simple, and the degrees of freedom of the plane are higher than that of the other support types. For such a shear-type damper, an H-shaped cross-section with a panel made of a highly ductile material, such as a low-yield-point steel, is generally adopted. This study used a low-yield-point steel circular hollow-section damper, which was installed in the frame as a stud support form, and a case was used to receive the in-plane force. For the damper to function effectively in the frame, it was necessary to determine the elastoplastic mechanical properties of the damper and the dampers supported by the stud. The mechanical properties of the damper unit and damper system with the stud were examined by cyclic loading test. An H-shaped shear panel damper was used as the control group with almost the same full plastic shear strength, initial stiffness, and weight as the circular hollow-section damper and the cyclic loading test was conducted under the same conditions. The effectiveness of the low-yield-point steel circular hollow-section damper was examined as a shear-type hysteretic damper by comparing both. In addition, a nonlinear finite element analysis was performed to determine the influence of the initial stiffness on the damper supported by the stud.

Evaluation of Behavior of Hybrid Beam Combining Steel Inverted T-Section and RC Flange

This paper deals with flexural investigation of a type of steel-concrete composite beam structure able to provide an adequate bond between steel and concrete elements through the application of a simple steel reinforcement shear connector design, steel reinforcing bars bent into L-shapes. The cross sections involve inverted steel T-beam being embedded within reinforced concrete (RC) flange of the slab. The paper concentrates on elastic and elastic-plastic behaviour of steel inverted T-beam entrenched within a reinforced concrete flange at the top. In addition, shear connection was investigated in detail. Finally, some suggested designing equations and curves simulating the elastic, elastoplastic and full plastic experimental moments were developed. The plastic theoretical study results coincides with the experimental behaviour of the developed model.

Evaluation of ultimate strength of exposed column bases considering the bearing stress of foundation concrete

Exposed column bases are widely used in low-to-medium rise steel structures. As they can transfer all the loads from the superstructure to the sub-system, exposed column bases are in the most severe state of stress. Further, they show various failure modes because of the complex stress transfer mechanism. One of the failure modes stated in the Japanese design recommendations are the yielding of anchor rods. To ensure the yielding of anchor rods, the bearing failure of foundation concrete must be prevented. However, studies on the bearing stress of exposed column bases are limited. In the present study, the existing calculation methods for the bearing stress of exposed column bases are summarized. A database of previous experimental studies on exposed column bases was also established to analyze the calculation methods. To normalize the experimental results in the database, an experiment was conducted on full-scale, exposed column bases, and a method was proposed to obtain the full plastic moment for further analysis. With the proposed method, the accuracy and applicability of the calculation methods were verified. Furthermore, considering the design philosophy in Japan, a more conservative method to calculate bearing stress was proposed.

The climate cost of saving water by different plastic mulching patterns

Global water shortage and climate change are two of the most significant challenges for our planet, and how to coordinate their relationship is a problem unsolved. In this study, we proposed the synchronization index of water-saving and CO2 mitigation to evaluate the climate cost of saving water by different plastic mulching patterns and explore way to improve the synchronization. The water-saving performance, carbon footprint, and the synchronization index were analyzed for three typical plastic mulching patterns, namely conventional partial plastic mulching, full plastic mulching, and “one film for two years” mulching. The results indicated that all three types of plastic mulching systems were effective in reducing the water footprint of crop production, with full plastic mulching showing the best performance in terms of improving crop yields and water savings. The application of plastic mulching mainly influences the carbon footprint through increasing indirect greenhouse gas emission, accelerating soil organic carbon decline and increasing N2O emission. Area-scale carbon footprint showed a significant positive relationship with the input amounts of plastic film, and the sort order of yield-scale carbon footprint was partial plastic mulching > full plastic mulching > “one film for two years” mulching. Calculated synchronization index was -0.35 kg CO2-eq m−3, -0.10 kg CO2-eq m−3, and 0.50 kg CO2-eq m−3 for partial plastic mulching, full plastic mulching, and “one film for two years” mulching, respectively. Full plastic mulching and partial plastic mulching resulted in an additional 0.35 and 0.10 kg of CO2-eq for saving one cubic meter of water, and only “one film for two years” mulching resulted in simultaneous water savings and greenhouse gas mitigation. This study suggests that water savings achieved using conventional partial plastic mulching have costs in terms of climate change. Faced with the dual pressure of global water shortages and climate change, controlling input amounts of plastic film and prolonging the lifetime of the film are simple and effective way to coordinate water savings and greenhouse gas mitigation. Moreover, the results of this study suggested that water savings and GHG emission mitigation cannot necessarily be achieved simultaneously and that searching for both water-saving performance and its synchronization with GHG mitigation should become a new paradigm for the development of water-saving technologies in the future.

ARTISTIC REFLECTION OF HISTORICAL AND ARCHITECTURAL MONUMENTS IN THEATRICAL AND DECORATIVE ART

The artist's job in the theater is to find the perfect composition of the stage design, which reveals the idea-artistic style of the play, clarifies the idea and purpose of the playwright and director, and achieves its solution in detail and color. This has always made the show more well-groomed, impressive and memorable. The creative artist finds the general harmony of the scene in the form of full plastic thinking, creating the artistic and figurative world of the play, the form of expression, the compositional proportions, the drama and the exact scale of the colors. All this is done with the help of various means of expression in the stage. The compositional solution, colors, perspective issues play a key role in the performance. Part of the stage design is theatrical architecture, along with intricate and varied decorative structures. Architectural patterns in theatrical performances have a certain amount of detail in different styles.

Increase in Elastic Stress Limits by Plastic Conditioning: Influence of Strain Hardening on Interference Fits

This paper presents a novel method for the design of purely elastic interference fits by exploiting the plastic properties of a material. In this process, the elastic potential of the material is expanded by the targeted application of residual stresses and material strengthening, in such a way that additional operational loads due to rotating bending moments, torsion, temperature changes, and centrifugal forces are absorbed by the hub in a purely elastic manner, and plastic deformations are avoided. In the ideal case, the performance shown by the connection can be almost doubled compared to conventional elastically joined interference fits. Compared with conventional elastically–plastically joined interference fits, a specifically defined additional safety against plastic deformation can be guaranteed. In addition to the prerequisites of plasticity theory, the fundamental aspects of the process are presented and investigated on the basis of two-dimensional numerical calculation models. Both ideal plastic and hardening material models were used. The results of this work showed that previous stress limits can be significantly increased up to full plastic loading and that the utilization of plastic material properties is also made possible by plastic conditioning for applications that were previously designed to be purely elastic.

Reliability Comparisons of Cervical Active Range of Motion Measuring Methods: Universal Goniometer versus Virtual Reality

The purpose of this research study is to compare the reliability of measuring active cervical range of motion performed with the universal goniometer with an FDA approved XRHealth virtual reality computer program and the Oculus Rift. Methods: The design of the study is a single-blinded randomized controlled study. A sample size of 40 adults was recruited via email, posters, and person to person recruitment. The sample was comprised of males and females, ages 20 to 72-year-old. Equipment included a large universal goniometer with 12-inch arms and a covered full circle plastic body, oculus rift with a computer, VR Health System, chair with arms and a gait belt to control for trunk movements. All four investigators underwent a training session in the measurement of cervical range of motion utilizing a universal goniometer. Each participant was measured with each tool twice. Results: Virtual reality demonstrated a statistically significant difference from the standard goniometer methods at a 99% confidence level (p=0.01). Both tools (goniometer and virtual reality) were found to have good to excellent inter-rater reliability. Conclusion: This study suggests a virtual reality method can be used as a reliable clinical tool in comparison with the universal goniometric cervical active range of motion measurement. Recommendations for future studies should be focused on establishing the validity of virtual reality as an assessment tool using a larger sample size with a wide age range and those who have current cervical discomfort or are experiencing functional limitations in cervical ranges of motion.

STUDY ON CONTACT MECHANICS MODELING OF JOINT SURFACE CONTAINING COMPOSITE MATERIALS

A large number of heterogeneous joint surfaces containing composite materials between machine tool and foundation seriously affects the mechanical properties of machine tools. The calculation method of equivalent elastic modulus of reinforced composites is proposed according to the theory of composite mechanics. Then, based on fractal theory, considering the whole process of a single micro convex body from elasticity and elasto-plasticity to complete full plastic deformation, a modified micro mechanical behavior contact model of micro convex body is proposed. On this basis, a contact model of the complete joint surface is derived by using the statistical contact theory, and the mechanical model of the sectional structure is established by introducing the contact model. Finally, the modal experimental system is built to verify the accuracy of the proposed mechanical model. The proposed mechanical model can provide a basis for the design and assembly of segmental structure.

Kriging Model for Reliability Analysis of the Offshore Steel Trestle Subjected to Wave and Current Loads

Offshore steel trestles (OSTs) are exposed to severe marine environments with stochastic wave and current loads, making structural safety assessment challenging and difficult. Reliability analysis is a suitable way to consider both wave and current loading intensity uncertainties, but the implicit and complex limit state functions of the reliability analysis usually imply huge computational costs. This paper proposes an efficient reliability analysis framework for OST using the kriging model of optimal linear unbiased estimation. The surrogate model is built with stochastic waves, current parameters, and the corresponding load factors. The framework is then used to evaluate the reliability of an example OST subjected to wave and current loads at three limit states of OST, including first yield (FY), full plastic (FP), and collapse initiation (CI). Three different distributions are used for comparison of the results of failure probability and reliability index. The results and the computational cost by the proposed framework are compared with that from the Monte Carlo sampling (MCS) and Latin hypercube sampling (LHS) method. The influences of sample number on the prediction accuracy and reliability index are investigated. The influence of marine growth on the reliability analysis of the OST is discussed using MCS and the kriging model. The results show that the reliability analysis based on the kriging model can obtain the reliability index for the OST efficiently with less calculation time but similar results compared with MCS and LHS. With the increase of the number of samples, the prediction accuracy of the kriging model increases, and the corresponding failure probability fluctuates greatly at first and then tends to be stable. The reliability of the example OST is reduced with the increase of marine growth, regardless of the limit state.

A New Design Problem in the Formulation of a Special Moment Resisting Connection Device for Preventing Local Buckling

In the present paper an improved formulation devoted to the optimal design problem of a special moment resisting connection device for steel frames is proposed. This innovative device is called a Limited Resistance Plastic Device (LRPD) and it has been recently proposed and patented by some of the authors. It is thought to be preferably located at the extremes of the beam, connecting the beam end cross section with the relevant column. The typical device is a steel element characterized by symmetry with respect to three orthogonal barycentric planes and constituted by a sequence of three portions with abrupt cross section changes. The main novelty of the present proposal is related to the design of special geometry for the optimal device ensuring that it possesses a reduced resistance with respect to the relevant connected beam element, is characterized by an equivalent bending stiffness equal to the one of the connected beam elements and exhibits full plastic deformations avoiding any local instability phenomenon. The optimal design is formulated as a minimum volume one and is subjected to suitable constraints on the geometry of the device and on its elastic and plastic behavior. The optimization problem is a strongly non-linear programming one and it is solved by adopting an interior-point algorithm that is available in the MATLAB Optimization Toolbox. The numerical simulations are devoted to the most used standard steel profiles (IPE, HE) and the results prove the great reliability of the proposed device. In addition, the relevant elastic and plastic domains of the designed devices are defined, and the expected behavior of the device is verified by appropriate 3D finite element models in the ABAQUS environment.

Bending and flexural-buckling strength of steel members considering strain-rate-effects at elevated temperatures

PurposeIn this study, the bending strength, flexural buckling strength and collapse temperature of small steel specimens with rectangular cross-sections were examined by steady and transient state tests with various heating and deformation rates.Design/methodology/approachThe engineering stress and strain relationships for Japan industrial standard (JIS) SN400 B mild steels at elevated temperatures were obtained by coupon tests under three strain rates. A bending test using a simple supported small beam specimen was conducted to examine the effects of the deformation rates on the centre deflection under steady-state conditions and the heating rates under transient state conditions. Flexural buckling tests using the same cross-section specimen as that used in the bending test were conducted under steady-state and transient-state conditions.FindingsIt was clarified that the bending strength and collapse temperature are evaluated by the full plastic moment using the effective strength when the strain is equal to 0.01 or 0.02 under fast strain rates (0.03 and 0.07 min–1). In contrast, the flexural buckling strength and collapse temperature are approximately evaluated by the buckling strength using the 0.002 offset yield strength under a slow strain rate (0.003 min–1).Originality/valueRegarding both bending and flexural buckling strengths and collapse temperatures of steel members subjected to fire, the relationships among effects of steel strain rate for coupon test results, heating and deformation rates for the heated steel members were minutely investigated by the steady and transient-state tests at elevated temperatures.

Optimizing the impact of film mulching pattern and nitrogen application rate on maize production, gaseous N emissions, and utilization of water and nitrogen in northwest China

Film mulching and nitrogen fertilization are two effective practices to promote maize production in northwest China, but their impacts on environment in terms of greenhouse gas emission remain unclear. Two-year field trials were conducted to 1) explore the effect of the film mulching pattern and N fertilization rate on maize production, gaseous N emission, and utilization of N and water; 2) find an optimal mulching pattern and N-fertilization rate to achieve green development. Trial Ⅰ included flat planting with non-mulching (NM), ridge-furrow with plastic film mulch (PM), ridge-furrow with biodegradable film mulch (BM), and flat planting with full plastic film mulching (FM). Trial Ⅱ involved BM with N-fertilization rates (0, 90, 180, and 270 kg N ha−1), denoted as BMN0, BMN1, BMN2, and BMN3, respectively. The results showed that film mulching significantly decreased the daily flux and cumulative flux of gaseous N by an average of 32.02%, 35.17% (NH3), 78.70%, 75.83% (N2O), respectively, as compared with NM. Film mulching also significantly increased the amount of soil residual mineral N after harvest, plant N uptake, and soil water storage but decreased evapotranspiration by an average of 8.31%, 9.42%, 17.45%, and 25.34%, respectively, as compared with NM. In addition, grain yield, water use efficiency (WUE), N uptake efficiency (UPE) (except for BM), N harvest index (NHI), N use efficiency (NUE), and partial productivity of N (PNP) were significantly higher in the mulching treatments, and yield–scaled NH3 emission (YSN) was significantly lower in PM and BM, as compared with NM. Compared with FM, soil residual mineral N after harvest, plant N uptake, grain yield, WUE, NUE, and PNP were significantly lower but NHI was significantly higher in PM and BM. The daily flux and cumulative flux of N2O emission and the amount of soil residual NO3− -N after harvest were significantly lower but plant N uptake was significantly higher in PM than in BM. Collectively, BM was the best mulching treatment in this study. With increase of N-fertilization rate, the daily flux and cumulative flux of NH3 volatilization, the peak period, and the cumulative flux of N2O emission, the grain yield, WUE, NUE (except for N3), and YSN were significantly increased but NHI, PNP, and UPE were significantly decreased. The optimum N-fertilization rate under BM was found at 173 kg ha−1, which could achieve the goal of high yield, efficient utilization of water and nitrogen, and environmental friendliness.

Straw strip mulching in a semiarid rainfed agroecosystem achieves winter wheat yields similar to those of full plastic mulching by optimizing the soil hydrothermal regime

Straw strip mulching (SM) is a new mulching technology. From 2012 to 2018, SM’s effects on soil moisture and temperature and production performances were compared with other mulching practices, using three treatments: full-cover plastic mulch (PM), no mulch with wheat sown in rows as the control (CK), and SM with 50% to 59% of the field area mulched. Compared with CK, on average over six growing seasons, SM and PM increased grain yield by 27.0% and 21.7%, straw yield by 21.6% and 22.6%, kernels ha−1 by 26.6% and 19.0%, net income by 29.8% and −25.0%, soil temperature at 5 cm by −1.5 °C and 0.2 °C from overwintering to maturity, and soil water storage at 0–200 cm by 25 and 22 mm, respectively. The increase in soil moisture in SM and PM was greater in the early period (overwintering to jointing) than in the later period (booting to maturity) and at 0 to 120 cm than at 120–200 cm in the early period. Although the mean evapotranspiration of whole growth period across six seasons was similar among treatments, SM and PM increased water consumption during the key formation period of yield components after overwintering by 16 and 32 mm, respectively, while reducing it before overwintering. Compared with CK, SM and PM had the effects of warming during overwintering and cooling after jointing. By increasing water consumption after overwintering and ratio of transpiration to evapotranspiration and providing favorable soil temperature for multiple growth stages and more sufficient soil moisture, SM and PM promoted vegetative growth and increased kernels ha−1, the main mechanisms by which SM and PM increased grain yield relative to CK. Relative to PM, SM is a more economically beneficial and environment-friendly technology for dryland wheat production.